Summary

XenDesktop discovery: Installation and access requirements

Synopsis

The beacon must be installed and must be able to directly communicate with the XenDesktop broker.

The XenDesktop broker must allow remotely signed PowerShell scripts to be run.

See Knowledge Base Article - Set up Remote Powershell for XenDesktop discovery

You can check to see the execution policy on the XenDesktop broker server by opening a PowerShell window and running the following PowerShell command:
Get-ExecutionPolicy

Ensure the policy is either RemoteSigned, AllSigned, or Unrestricted (not recommended). If it is Restricted, run the following command to set it to RemoteSigned using the following PowerShell command: 
Set-ExecutionPolicy RemoteSigned

Ensure the server running the beacon also has a similar PowerShell execution policy so it can run the required PowerShell commands to communicate with the XenDesktop broker.
Ensure the password store on the beacon has an entry for the XenDesktop server.

Troubleshooting
Review the beacon logs for errors relating to XenDesktop discovery %PROGRAMDATA%\Flexera Software\Compliance\Logging\BeaconEngine
Turn on tracing by modifying <INSTALL DIR>\Flexera Software\Inventory Beacon\etdp.trace and enabling the Scheduling/RemoteExecution tracing option