One of the possible reasons that the administrator is not seeing the printers within his Horizon Desktop session is that printing is disabled in the Horizon Desktop Pool. Printing is a feature that allows users to print from a remote desktop to any local or network printer available on their client device. Printing can be enabled or disabled for each desktop pool by using the VMware Integrated Printing feature.

VMware Integrated Printing is a feature that supports client printer redirection, location-based printing, and persistent print settings. Client printer redirection enables users to print from a remote desktop to any local or network printer available on their client device. Location-based printing enables users to print to network printers that are physically near their client device. Persistent print settings enable users to retain their print settings across sessions.

To enable or disable printing for a desktop pool, the administrator needs to follow these steps:

• In Horizon Console, select Inventory > Desktops.
• Select the desktop pool and click Edit.
• In the Edit Desktop Pool dialog box, select the VMware Integrated Printing tab.
• Select or clear the Enable VMware Integrated Printing check box.
• Click OK.

If printing is disabled for a desktop pool, users will not see any printers within their Horizon Desktop session, even if they have installed the VMware Integrated Printing feature in the Horizon Agent and the Horizon Client. Therefore, to resolve this issue, the administrator needs to enable printing for the desktop pool by selecting the Enable VMware Integrated Printing check box.

The other options are not likely to be the reason that the administrator is not seeing the printers within his Horizon Desktop session:

• Port TCP 9427 is disabled: This port is used by the VMware Integrated Printing feature for communication between the Horizon Agent and the Horizon Client. If this port is disabled, users might experience printing errors or delays, but they should still see the printers within their Horizon Desktop session.
• The VMware Integrated Printing feature is not installed in the Horizon Client: This feature is installed by default in the Horizon Client for Windows, Mac, Linux, Chrome, and HTML Access. If this feature is not installed in the Horizon Client, users might not be able to print from their remote desktops, but they should still see the printers within their Horizon Desktop session.
• Port TCP 32111 is disabled: This port is used by ThinPrint for communication between the Horizon Agent and the ThinPrint Client. ThinPrint is a legacy printing feature that has been replaced by VMware Integrated Printing. If this port is disabled, users might experience printing errors or delays with ThinPrint, but they should still see the printers within their Horizon Desktop session if they use VMware Integrated Printing.

References: Configuring VMware Integrated Printing, Enable or Disable Printing for a Desktop Pool, and [VMware Horizon 8.x Professional Course]

VMware Horizon's Dynamic Environment Manager (DEM) is designed to provide a consistent and personalized desktop experience for users across different sessions and desktops. DEM manages user profiles and policies dynamically, ensuring that user settings, preferences, and application configurations are consistent no matter which desktop a user connects to, thus meeting the requirement for a uniform desktop experience.

Application Profiler is a tool that analyzes the registry and file system locations where the settings for a particular application are stored, and creates a Flex configuration file for use with Dynamic Environment Manager. Application Profiler is installed using VMware Dynamic Environment Manager Enterprise Setup Wizard and explicitly selecting local drive installation1. This option allows you to install Application Profiler on a separate machine from the Dynamic Environment Manager Agent or Management Console. Alternatively, you can install Application Profiler on the same machine as the Dynamic Environment Manager Agent or Management Console, by selecting network share installation1.

VMware Dynamic Environment Manager Agent and the Application Profiler can be installed on the same machine, but it is not recommended. This is because the Dynamic Environment Manager Agent might interfere with the profiling process by applying settings to the application being profiled1. Therefore, it is best to use a clean system for profiling applications.

Application Profiler is not installed automatically when installing VMware Dynamic Environment Manager FlexEngine or Management Console. FlexEngine is the component that applies the user environment settings during logon, logoff, and session reconnect or disconnect events2. Management Console is the component that allows you to configure and manage the user environment settings2. Neither of these components requires Application Profiler to function. Application Profiler is an optional tool that helps you create Flex configuration files for applications that are not included in the predefined settings library1. References:

• VMware Dynamic Environment Manager Overview2
• Using Application Profiler1

To improve the user experience when using Application Profiler from Dynamic Environment Manager to create application-specific user defined settings, the administrator can configure exclusions to filter out unnecessary folders and registry entries. Exclusions are rules that specify which file system or registry locations are not included in the Flex configuration file. Exclusions can reduce the size of the Flex configuration file and the profile archive, and improve the performance of the application profiling and synchronization processes12.

The other options are not valid or effective because:

• Changing the default save path does not affect the size or content of the Flex configuration file or the profile archive. It only changes where the files are stored on the local machine3.
• Using Deepest Registry Path does not reduce the size of the Flex configuration file or the profile archive. It only changes how the registry locations are displayed in the Application Profiler interface4.
• There is no such thing as Cloud Entitlements in Dynamic Environment Manager. The correct term is Global Entitlements, which are used in Cloud Pod Architecture to entitle users to desktops or applications across multiple pods5.

References := 1: VMware Dynamic Environment Manager Application Profiler Administration Guide: Filtering and Optimizing the Analysis Details 2: VMware Dynamic Environment Manager Application Profiler Administration Guide: Exclusions 3: VMware Dynamic Environment Manager Application Profiler Administration Guide: Advanced Configuration of Application Profiler 4: VMware Dynamic Environment Manager Application Profiler Administration Guide: Editing the Flex Configuration File 5: VMware Horizon 8 Documentation: Understanding Global Entitlements in Cloud Pod Architecture

VMware Horizon Cloud on Microsoft Azure is the only deployment solution that meets all the requirements. VMware Horizon Cloud on Microsoft Azure supports Windows 10 Enterprise multi-session desktops, which are a new Remote Desktop Session Host exclusive to Azure Virtual Desktop on Azure1. It also supports App Volumes, which is a real-time application delivery system that enables IT to instantly provision applications to users or desktops. VMware Horizon Cloud on Microsoft Azure supports centralized brokering, which means that the Horizon Cloud Service acts as a single point of entry for end users to access their virtual desktops and applications. VMware Horizon Cloud on Microsoft Azure also supports automatic routing of end-users to the most appropriate virtual workspace, using the Universal Broker feature. Universal Broker is a cloud-based brokering service that provides a unified user experience across multiple Horizon pods and clouds.

VMware vSphere Desktop Edition does not support Windows 10 Enterprise multi-session desktops, as they are only available on Azure Virtual Desktop1. VMware Workspace ONE Unified Endpoint Management does not support App Volumes, as it is a different solution for managing devices and applications. VMware Horizon On-Premises does not support automatic routing of end-users to the most appropriate virtual workspace, as it requires manual configuration of load balancing and global entitlements. References:

• Profile production applications in Azure with Application Insights Profiler1
• Using Application Profiler - VMware Docs2
• First look at profiling tools - Visual Studio (Windows)3
• App Volumes Overview
• Horizon Cloud Service on Microsoft Azure Architecture
• Universal Broker Overview
• Workspace ONE UEM Overview
• Load Balancing Across Pods and Sites in a Cloud Pod Architecture Environment

To enable debug logging for a single user in VMware Dynamic Environment Manager, the administrator needs to create an empty FlexDebug.txt file in the same folder as the standard log file for this user. This will trigger FlexEngine to switch to debug logging for this particular user1. Debug logging is useful for troubleshooting purposes, as it provides more detailed information about the FlexEngine operations and actions1.

The other options are not correct because:

• Updating the FlexEngine registry to DEBUG will not enable debug logging for a single user, but for all users who log on to the same computer. This option can only be set through Group Policy settings and applies to all users1. Moreover, this option is not recommended, as it can cause performance issues and disk space consumption due to the large size of the log files1.
• Creating an empty FlexDebug.log file in the log folder will not enable debug logging for a single user, as the file name must be exactly FlexDebug.txt. The file extension must be .txt, not .log1.
• Configuring the FlexEngine GPO to DEBUG will not enable debug logging for a single user, but for all users who are affected by the GPO. This option can only be set through Group Policy settings and applies to all users1. Moreover, this option is not recommended, as it can cause performance issues and disk space consumption due to the large size of the log files1.

References:

• Enabling debug logging for a single user in VMware Dynamic Environment Manager1

The reason for the issue is that the administrator may not have added an instant clone domain administrator to VMware Horizon. This is a requirement for creating an automated farm of instant-clone virtual machines using the Add Farm wizard.

An instant clone domain administrator is a user account in Microsoft Active Directory that allows Connection Server to perform certain operations related to instant clones in Active Directory, such as joining instant-clone virtual machines to the domain, creating computer accounts, and deleting computer accounts. The administrator must create and configure this account in Active Directory and then specify the user name and password in VMware Horizon.

To add an instant clone domain administrator to VMware Horizon, the administrator needs to follow these steps:

• In the Horizon Console, select Settings > Domains > Domain Accounts.
• Click Add.
• Enter the domain, user name, and password for the instant clone domain administrator.

After adding the instant clone domain administrator to VMware Horizon, the administrator can proceed with creating an automated farm of instant-clone virtual machines using the Add Farm wizard.

The other options are not the reason for the issue:

• In the Add Farm wizard, the administrator may not have selected Automated Farm as farm type: This option is not relevant to the issue, as the farm type selection is done in a later page of the Add Farm wizard, after selecting the domain and the AD container. The page displayed in the exhibit is the Identification and Settings page, which is the first page of the Add Farm wizard.
• The administrator did not prepare a RDSH golden image snapshot: This option is not relevant to the issue, as the RDSH golden image snapshot selection is done in a later page of the Add Farm wizard, after selecting the domain and the AD container. The page displayed in the exhibit is the Identification and Settings page, which does not require a RDSH golden image snapshot.
• The administrator did not add the RDSH golden image to the correct domain: This option is not relevant to the issue, as the RDSH golden image domain selection is done in a later page of the Add Farm wizard, after selecting the domain and the AD container. The page displayed in the exhibit is the Identification and Settings page, which does not require a RDSH golden image domain.

References: Configuring an Instant Clone Domain Administrator in Active Directory, Add an Instant-Clone Domain Administrator, and [VMware Horizon 8.x Professional Course]

The action that must first be performed to ensure that there are no issues with Horizon LDAP replication within the Pod is to execute repadmin.exe/showrepl localhost:389. This command will display the replication status of the local Connection Server instance and show any errors or warnings that might affect the replication process1. The administrator should run this command on each Connection Server instance in the Pod before upgrading them in parallel, and resolve any issues that are reported.

The other options are not valid or feasible because:

• Executing ViewDBChk.cmd --scanMachines will not check the Horizon LDAP replication status, but rather scan the vCenter Server inventory for virtual machines that are managed by Horizon and report any inconsistencies or errors2. This command is useful for troubleshooting virtual machine issues, but not for verifying LDAP replication.
• Executing vdmexport.exe -f Myexport.lDF will not check the Horizon LDAP replication status, but rather export the Horizon LDAP configuration data to a file named Myexport.lDF3. This command is useful for backing up or restoring the Horizon LDAP data, but not for verifying LDAP replication.
• Executing vdmadmin.exe -S will not check the Horizon LDAP replication status, but rather display the health status of the Connection Server instances in the Pod4. This command is useful for monitoring the Connection Server performance and availability, but not for verifying LDAP replication.

References:

• Repadmin Examples1
• ViewDBChk Tool2
• Back Up Horizon Configuration Data3
• Display Health Status Information4

If the Horizon Console does not display the health status of configured Unified Access Gateways (UAGs), it could be due to improper firewall configuration blocking traffic on port 443, which is essential for secure communication. Additionally, a discrepancy between the system name in UAG and the name entered in the Horizon Console can also prevent the console from correctly retrieving and displaying the UAG's health status.

To expand a Writable Volume in VMware Horizon, the administrator needs to navigate to the Volumes > Writables section in the Horizon Console, select the specific volume, and choose the option to update or expand the writable volume. The new size specified must be at least 1GB larger than the current size to ensure there is enough space for the expansion process and to accommodate the growth of user data.

Single sign-on (SSO) is a feature that allows users to log in to Horizon Client once and launch remote desktops and applications without being prompted for credentials again. SSO is enabled by default and can be configured in the Global Settings of Horizon Administrator. One of the settings is SSO Timeout, which determines how long the user’s credentials are cached before they expire. If the SSO Timeout is too short, users might be frequently asked for credentials when opening additional apps. To resolve this issue, the administrator can increase the SSO Timeout value or set it to -1, which means that no SSO timeout limit is set. References: Global Settings for Client Sessions in Horizon Console and [VMware Horizon 8.x Professional Course]

https://docs.vmware.com/en/VMware-Horizon-7/7.13/horizon-console-administration/GUID-E2A7CA32-193D-43D9-B08E-DD20CAE9CA28.html

In a load balanced Horizon POD with three Connection Servers, there are 450 active Blast sessions connected. If one of these Connection Servers runs into an unplanned outage, only the active sessions from the failed Connection Server are disconnected, because HTTPS Secure Tunnel is disabled. This means that the other two Connection Servers can still handle the remaining sessions without interruption.

The HTTPS Secure Tunnel is a feature that allows Horizon Client devices to establish secure connections to virtual desktops and applications through the Connection Server. When this feature is enabled, all the display protocol traffic is tunneled through the Connection Server, which acts as a proxy between the client and the desktop. This increases the security and simplifies the network configuration, but also adds some overhead and dependency on the Connection Server availability1.

When this feature is disabled, the Horizon Client devices connect directly to the desktops using their IP addresses or hostnames, bypassing the Connection Server. This reduces the load and dependency on the Connection Server, but also requires more network configuration and firewall rules to allow direct access to the desktops2.

The Blast Secure Gateway is a similar feature that allows Horizon Client devices to establish secure connections to virtual desktops and applications using the Blast Extreme protocol through the Connection Server. When this feature is enabled, the Blast Extreme traffic is tunneled through the Connection Server, which acts as a gateway between the client and the desktop. When this feature is disabled, the Horizon Client devices connect directly to the desktops using Blast Extreme3.

In this scenario, both HTTPS Secure Tunnel and Blast Secure Gateway are disabled, which means that the Horizon Client devices connect directly to the desktops using Blast Extreme. Therefore, if one of the Connection Servers fails, only the sessions that were authenticated by that Connection Server are affected. The other sessions can continue without interruption, as long as they can reach their desktops directly4.

The other options are not correct for this scenario:

• All 450 active sessions are disconnected, and have to re-connect again by the end-user. This would be true if HTTPS Secure Tunnel or Blast Secure Gateway were enabled, and all the display protocol traffic was tunneled through the Connection Server. In that case, any failure of a Connection Server would disconnect all the sessions that were using it as a proxy5.
• All active sessions will stay connected, because HTTPS Secure Tunnel and Blast Secure Gateway are disabled. This would be true if there was no dependency on the Connection Server after authentication. However, even with HTTPS Secure Tunnel and Blast Secure Gateway disabled, there is still some communication between the Horizon Client and the Connection Server for session management and heartbeat monitoring. If a Connection Server fails, these communications are lost and the sessions are terminated.
• All 450 active session are logged off immediately. This would be true if there was a global setting in Horizon Console to log off users when a Connection Server fails. However, there is no such setting in Horizon Console. The default behavior is to disconnect users when a Connection Server fails, not log them off.

References:

• Configuring HTTPS Secure Tunnel
• Configuring Network Ports for Direct Connections
• Configuring Blast Secure Gateway
• Load Balancing Across Multiple Pods
• Horizon 7: Monitoring health of Horizon Connection Server using Load Balancer
• [Horizon 7 Pods]
• [Global Settings for Client Sessions in Horizon Console]
• [VMware Horizon Architecture Planning]

VMware Horizon Client Configuration

VMware Dynamic Environment Manager Application Profiler is a standalone application that simplifies the creation of Flex configuration files and predefined settings for use with VMware Dynamic Environment Manager. Application Profiler analyzes where an application stores its file and registry configuration. The analysis results in an optimized Flex configuration file, which you can edit in the Application Profiler or use directly in the VMware Dynamic Environment Manager environment. With Application Profiler, you can also create application-specific predefined settings, with which you can set the initial configuration state of applications. Save the Flex configuration file with predefined settings to export the current application configuration state1.

Therefore, the two capabilities that are supported by VMware Dynamic Environment Manager Application Profiler are:

• It allows creation of application-specific predefined settings. This means that you can configure the default settings for an application that will be applied when a user launches it for the first time. For example, you can set the language, theme, or preferences of an application using Application Profiler2.
• It analyzes registry and file system location settings for an application. This means that it monitors the changes that an application makes to the registry and file system when it is running, and generates a Flex configuration file that captures those changes. This allows VMware Dynamic Environment Manager to manage the user personalization of those settings across different devices and sessions3.

The other options are not supported by VMware Dynamic Environment Manager Application Profiler:

• It allows individual user personalization of applications. This is not a capability of Application Profiler, but rather of VMware Dynamic Environment Manager itself. Application Profiler only helps to create the Flex configuration files that enable user personalization, but it does not apply them to individual users4.
• It allows third-party user personalization of applications. This is also not a capability of Application Profiler, but rather of VMware Dynamic Environment Manager itself. Application Profiler only works with applications that store their settings in the registry or file system, and does not support third-party user personalization solutions such as AppSense or RES.
• It allows creation of computer templates. This is not a capability of Application Profiler at all. Computer templates are used to create virtual machines or physical computers with a predefined configuration, and are not related to application management or user personalization.

References:

• Introduction to VMware Dynamic Environment Manager Application Profiler
• Editing a Profile Archive
• Profile an Application
• Introduction to VMware Dynamic Environment Manager
• [VMware Dynamic Environment Manager FAQ]
• [Create a Computer Template]

Collaboration is a feature that allows users to invite other users to join an existing Windows or Linux remote desktop session with both screen sharing and audio out features enabled. A remote desktop session that is shared in this way is called a collaborative session. The user that shares a session with another user is called the session owner, and the user that joins a shared session is called a session collaborator. A Horizon administrator must enable the Session Collaboration feature for the desktop pool or farm that contains the remote desktops that support collaboration.

One of the requirements to enable Session Collaboration is to use the VMware Blast display protocol for the remote desktops. VMware Blast is a protocol that provides high-performance, high-quality graphics and multimedia delivery over LAN or WAN networks. VMware Blast supports Session Collaboration by allowing multiple users to view and interact with the same remote desktop session simultaneously. Other display protocols, such as PCoIP or RDP, do not support Session Collaboration and will not allow users to share or join collaborative sessions.

Therefore, to enable Session Collaboration in the VMware Horizon environment, the administrator needs to use the BLAST protocol as a requirement. References: Configuring Session Collaboration, Sharing Remote Desktop Sessions, and [VMware Horizon 8.x Professional Course]

Thin Clients and Zero Clients have the lowest cost of ownership and are easier to manage due to their minimalistic design, which lacks a full operating system, resulting in fewer components that require updates. These clients are designed for remote desktop services like VMware Horizon, where the computing work is done on the server side, making firmware updates and monitoring simpler and more centralized.

A screenshot of a computer program Description automatically generated

VMware Horizon is designed to deliver a virtual desktop and application infrastructure, providing IT with a modern, streamlined approach to deliver, protect, and manage Windows and Linux virtual desktops and applications while containing costs and ensuring that end users can work anytime, anywhere, on any device. Horizon 8 supports flexible hybrid and multi-cloud deployment options and offers an optimized experience with unified communication and collaboration tools. The VMware Blast Extreme Protocol, included with Horizon 8, is a dynamic display protocol that delivers an immersive, feature-rich user experience across devices, locations, media, and network connections​​.

VMware Workspace ONE UEM (Unified Endpoint Management) is crucial for ensuring that end-user devices comply with an organization's IT policies. It manages and secures endpoints like smartphones, tablets, laptops, and desktops, streamlining operational tasks for IT while ensuring corporate data security.

VMware Workspace ONE Access facilitates secure and simplified access to enterprise applications, providing single sign-on capabilities and conditional access based on user authentication. This ensures that users can access the resources they need efficiently while maintaining the security of the organization's data and applications.

References:

• For more information on VMware Horizon 8 and its capabilities, you can refer to VMware's official documentation and resources available at techzone.vmware.com, which provides a comprehensive overview of Horizon 8, including its architecture, components, and deployment scenarios​​​​​​.
• Detailed insights into VMware Workspace ONE UEM and Workspace ONE Access can be found within VMware's product documentation and techzone resources, which offer guidance on implementing and managing these solutions as part of the Anywhere Workspace ecosystem​​.

For instant-clone operations in Active Directory, the user account used by VMware Horizon needs specific permissions to manage computer objects effectively. These include the ability to create and delete child objects and computer objects, as well as read and write all properties of those objects. These permissions ensure that Horizon can create, modify, and clean up computer accounts associated with instant clones, facilitating seamless desktop provisioning and management.

The user’s problem is that their settings for the e-mail client are not being saved across sessions. This means that their user profile, which contains their personal data, settings, and preferences, is not being preserved or synchronized properly. To solve this problem, the administrator can deploy one or more of the following options to manage user profiles in Horizon:

• VMware App Volumes Writable Volumes: This option allows users to store user-installed applications, data, and settings on a disk independent of the VM. Writable volumes can be attached to desktops along with application packages, and they can isolate the user-installed applications from the system-installed applications. Writable volumes can also be configured to capture specific files and registry keys by using the snapvol.cfg policy file. This option can help users retain their e-mail client settings on a writable volume that is attached to their desktop at each login.
• Persona Management: This option allows administrators to manage user profiles by using a remote repository that stores user profiles. Persona Management synchronizes the user profile between the remote repository and the local desktop at login, logout, and at regular intervals during the session. Persona Management also supports profile redirection, which allows administrators to redirect certain folders in the user profile to a network share or a writable volume. This option can help users access their e-mail client settings from the remote repository or the redirected folder at each login.
• VMware Dynamic Environment Manager: This option allows administrators to manage user profiles and policies by using a central share that stores user configuration files. Dynamic Environment Manager captures and applies user settings and preferences based on conditions and triggers, such as location, device, or application launch. Dynamic Environment Manager also supports profile archives, which allow administrators to back up and restore user profiles on demand or on schedule. This option can help users apply their e-mail client settings from the central share or the profile archive at each login.

The other options are not valid options for managing user profiles in Horizon:

• Roaming Profiles: This option is a native Windows feature that allows users to access their user profile from any computer in a domain by storing it on a network share. However, this option is not recommended for Horizon because it can cause long login times, profile corruption, and data loss due to its synchronous and overwrite behavior. Roaming profiles are also incompatible with instant clones and linked clones.
• Flexible profiles: This option does not exist in Horizon or Windows. It might be confused with Flex Profiles, which is a third-party product from Liquidware that provides profile management solutions similar to Dynamic Environment Manager.

References: Writable Volumes Overview, Configuring User Profiles with Horizon Persona Management, VMware Dynamic Environment Manager Overview, and [VMware Horizon 8.x Professional Course]

Enabling Quiesce Mode in the Unified Access Gateway (UAG) Admin UI is the recommended approach for minimizing downtime during maintenance or upgrades when the UAG is part of a load-balanced cluster. Quiesce Mode allows the UAG to stop accepting new connections while allowing existing sessions to continue until they naturally end. This ensures minimal disruption to users and allows for a controlled upgrade process.

To correctly sequence the TLS Certificate Configuration Steps:

• Get a new signed TLS certificate from a CA. Before making any modifications or importing the certificate, you'll first need to obtain a new signed TLS certificate from a Certificate Authority (CA). So, this should be Step 1.
• Import the TLS certificate into the Windows local computer certificate store. After obtaining the new signed TLS certificate, the next logical step is to import this certificate into the Windows local computer certificate store. This would be Step 2.
• Modify the certificates/ friendly names to vdm and reflect the current active certificate. Once the certificate is imported, the next step is to modify its friendly names to ensure the Horizon Service recognizes and uses this certificate. This becomes Step 3.
• Restart Horizon Service. Finally, after all the modifications and configurations are done, you should restart the Horizon Service to apply the changes. This is Step 4.

In summary:

A golden image must have a current snapshot to be used for cloning, and having multiple active snapshots can cause confusion and issues in the provisioning process. Additionally, selecting the correct Guest OS version is crucial for compatibility and optimal performance. These factors must be correctly configured for a VM to appear in the list of available golden images for provisioning.

A black screen when connecting to a Horizon virtual desktop can be caused by various reasons, such as network issues, hardware issues, Horizon tunnel issues, or underlying guest operating system issues. Based on the options given, the following could be the cause of the issue:

• A vRAM shortage on the Horizon virtual machine. This can affect the display performance and cause a black screen or a disconnect. To resolve this issue, you should configure the pool to provide enough video memory for the resolutions you plan to present to the clients1.
• The incorrect video driver version installed on the Horizon virtual machine. This can cause compatibility issues and prevent the display protocol from working properly. To resolve this issue, you should verify that the View desktop is using the correct video driver and that it is compatible with the VMware Tools and Horizon Agent versions installed23.
• An incorrect firewall configuration. This can block or misroute the display protocol traffic and cause a connection failure. To resolve this issue, you should verify that the required ports are open between the client, UAG/Security server/Connection server, and VDI machine4 .

The other options are not likely to cause a black screen when connecting to a Horizon virtual desktop:

• The client machine video memory is too high. This should not affect the display protocol performance or cause a black screen. The client machine video memory is only used to render the display on the local device, not on the remote desktop.
• The Horizon virtual machine video memory is too high. This should not cause a black screen or a disconnect either. The Horizon virtual machine video memory is used to allocate resources for the display protocol on the server side, not on the client side.

References:

• Dual monitors configured using PCoIP does not span both the monitors for VMware View and Connecting to a VDI desktop with PCoIP displays a black screen and disconnects after 10 seconds
• Error attaching to SVGADevTap, error 4000: EscapeFailed reported by PCoIP server
• Interoperability Matrices
• Configuring PCoIP Secure Gateway in VMware View
• [Network Ports in VMware Horizon]