Citrix “Cannot start app. Please contact your help desk.”

After standing up a new Citrix site from scratch, we found Citrix Receiver/Workspace apps configured on client workstations configured with SSO couldn’t launch applications.

After a few hours of checking event logs and enabling every Receiver/Workspace logging feature, I only found very generic errors. The most “relevant” error found in the Receiver/Workspace app log was:

Monday, January 13, 2020/4:24:30 PM ICA launch failed from delivery service at https://storefront.url/Citrix/Store/resources/v2/WERbunchofjunkBJQdfdBf4tUHdbWUgSGdbHRoIE1h/launch/ica; reason: GeneralAppLaunchError
Monday, January 13, 2020/4:24:30 PM Got Comms Error
Monday, January 13, 2020/4:24:30 PM Request failed: General error

Searching this error lead me to https://support.citrix.com/article/CTX133982

The Citrix article explains how to prepare a site for Pass-Through Authentication. Surprisingly, this parameter could be modified via the GUI in XenApp 6.5, but not newer.

Step two provides a PowerShell command which you can run on a site Delivery Controller:

asnp Citrix*
Set-BrokerSite -TrustRequestsSentToTheXmlServicePort $True

To validate the parameter took, run:

Get-BrokerSite

Validate TrustRequestsSentToTheXmlServicePort is set to True, then refresh Receiver/Workspace app and relaunch your application.