PowerShell XenDesktop SDK cmdlet Get-BrokerConnectionLog returns ConnectionFailureReason. This article lists the possible failure reasons and likely causes.
None - No failure (successful connection - session went active).
SessionPreparation - Failure to prepare session, typically Virtual Desktop Agent (VDA) refused ‘prepare’ call, or communication error on prepare call to VDA.
RegistrationTimeout - Timeout while waiting for worker to register when worker is being spun up to satisfy the launch.
ConnectionTimeout - Timeout while waiting for client to connect to VDA after successful brokering part.
Licensing - Licensing issue (for example - unable to verify a license).
Ticketing - Failure during ticketing, indicating that the client connection to VDA does not match the brokered request.
Other - Other