Problem Definition
Single sign-on (SsonSvr.exe) fails to start on a Windows XP client workstation when connecting to the client workstation through Remote Desktop Protocol (RDP). Customer reported issue only occurred after rebooting the workstation and leaving idle for over a few hours.
Environment
• Windows XP Professional with Service Pack 2
• ICA Client 9.2
Troubleshooting Methodology
1. Turned on process auditing on the XP Professional client workstation.
2. Reproduced the issue while process auditing was turned on. Review of the process auditing logs showed the following:
§ Expected Behavior for ssonsvr.exe start up (working):
o 11/3/2006 9:37:34 AM Security Success Audit process has been created: C:\Program Files\Citrix\ICA Client\ssonsvr.exe
o 11/3/2006 9:37:34 AM Security Success Audit process has been created: C:\Program Files\Citrix\ICA Client\ssoncom.exe
o 11/3/2006 9:37:32 AM Security Success Audit process has exited: C:\WINDOWS\system32\winlogon.exe
o 11/3/2006 9:37:32 AM Security Success Audit process has been created: C:\WINDOWS\system32\mpnotify.exe
o 11/3/2006 9:37:11 AM Security Success Audit process has been created C:\WINDOWS\system32\winlogon.exe
§ mpnotify.exe (a Microsoft process) is responsible for loading network providers including the ICA client’s single sign on network provider (pnsson.dll). Pnsson.dll is responsible for initiating ssonsvr.exe startup.
§ Observed behavior from the (non working) logs:
o 11/3/2006 12:37:52 PM Security Success Audit process has exited: C:\WINDOWS\system32\mpnotify.exe
o 11/3/2006 12:37:52 PM Security Success Audit process has been created: C:\WINDOWS\system32\mpnotify.exe
o 11/3/2006 12:37:52 PM Security Success Audit process has exited: C:\WINDOWS\system32\logon.scr
o 11/3/2006 12:37:52 PM Security Success Audit process has been created: C:\WINDOWS\system32\winlogon.exe
3. From all the process auditing logs collected, we saw that Winlogon.exe ends mpnotify.exe prematurely before the ICA Client Single Sign-on Network Provider (pnsson.dll) is loaded. This only occurred if logon.scr (screen saver) was running.
Resolution
As a workaround, the screen saver can be disabled by modifying the registry key HKEY_Users\.Default\Control Panel\Desktop ScreenSaveActive and setting it to 0 value.
Caution! This fix requires you to edit the registry. Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.
To resolve the issue, apply Microsoft private hotfix referenced in:
http://support.microsoft.com/kb/885423/en-us
More Information
CTX368624 – Troubleshooting Citrix Pass-through Authentication (Single Sign-On)
