Pass-through not working on Citrix XP FR4

Know this is an old (read realllllllly old) version of Citrix, but pretty much there has been zero budget to update it and zero incentive from management no matter what is said.

Anyways for me I have a Citrix farm running XP FR4 with the published app being JDE. The servers are running Windows 2003; can't go to 2008 due to application limitation which is a whole 'nother conversation.

Anyways in getting

when trying to connect to the farm using pass-through authentication. All settings on the client are set to use pass-through, security groups are part of the allow log on through terminal services (in GPO), and security groups assigned to published apps. Although it still allows to connect if you type domain credentials on the next loginscreen.

Upon further investigation, the ssonsvr.exe service is not running when trying to run the published app. This service is used for the pass-though authentication, so it not running is a small deal.

For me the fix that finally worked was installing ICA 10.0; any client version higher like 10.2 did not work.

 Next you need to double check the registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\NetworkProvider\Order. Double check ProviderOrder and make sure PnSson is first, if not edit it so it is.

After that should be all good