I’ll file this under “Stupid Things I Didn’t Know”. Citrix Presentation Server relies on the PATH variable for core components to run. I was adding to the PATH variable, in a scripted build after the CPS install and before a reboot, with a command like this:

C:\REG ADD "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /v Path /d "%PATH%;%ProgramFiles%\Sysinternals" /f

Unfortunately, that additions to the PATH that the CPS Setup program has added aren’t seen because I’m calling all this from the same session of CMD.EXE. After a reboot the server would not load the logon dialog and show this error instead:

The Logon User Interface DLL
C:\WINDOWS\system32\ctxgina.dll failed to load

Errors similar to the following are logged in the event viewer:

Event Type: Error
Event Source: IMAService
Event Category: None
Event ID: 3609
Date: 19/10/2005
Time: 1:48:18 PM
User: N/A
Computer: INGAUGBATS02
Description:
Failed to load plugin MfSrvSs.dll with error IMA_RESULT_FILE_NOT_FOUND

Setting the PATH back to what it should be will fix the issue. I’ll have to find a way to modify the registry entry directly, but my question to Citrix is: Why does Presentation Server rely on the PATH variable? Would it not read the location of files from the registry?