Today I was faced with a mysterious phenomemon. After getting the first Citrix XenApp 6.5 server farm up and running, I started to work on a second farm, that was installed in exactly the same fashion. The only difference between both farms was that the new farm would solely depend on a Citrix XenApp Services site, where the first farm used a Citrix XenApp Web Site.
When I started my test published application, aka Notepad, I was faced with the following error:
After starting a published application, the following error is shown
The weird part was that when I added a published desktop to the mix, it started just fine and Notepad would also run without any error message within that published desktop. So the error was not account or ACL based.
Along with the shown error message, an Event was also logged with Event ID 1480 in the Application Windows Log, saying ” Failed to launch application notepad with command line c:\windows\system32\notepad.exe . ensure the application is installed and user has permission to launch it.
Hopefull this would quickly let me google a solution it took me a long time reading alot of unsolved forum topics with a variety of tried fixes, it took me a long time to discover an ancient support article from Citrix, CTX996187 for MetaFrame XP. Even though the article was not updated after july 2003, I decided to have a look at the mentioned registry key.
So checking HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon, I discovered that the AppSetup (REG_SZ) only had the following data USRLOGON.CMD, where the registry key on the working XenApp 6.5 server in the other farm, showed a different value:
The winlogon registry key as found on the healthy XenApp server
When I changed the value on my broken XenApp 6.5 server and tested the Notepad published appliaction, to my surprise, it worked like a charm and I had a fully functional XenApp server back on track.
To ensure I will not lose alot of time fixing this error when I might run into it again in the future, I’ve written this blog and hope it can help others as well