Shadowing Issue

If you disable shadowing or enable shadowing but disable certain shadowing features during Setup, you cannot change the restrictions later. Any user policies you create to enable userto-user shadowing are subject to the restrictions you place on shadowing during Setup. Do not disable shadowing as a substitute for user- and group-specific connection policies.
But as you mentioned that you were able to shadow a month agao and I assume there is not re-install or upgrade of Citrix PS then please check the policy using PSC to see if you doing any restriction there. Try using "wshadow.exe" directly and see what's happening?

One more pint if Shadow option is not coming for 'Custom Administrator', please check if you have given them the permission to shadow. Try below: -
Log on a as a Full Administrator and modify the properties of the Custom Administrator. Custom Citrix Management Console Administrators must possess the ability to log on to Presentation Server Console under MetaFrame Administrators, View server information under Servers, and View session management under Sessions.

Using the administrator login, I could login to shadow Taskbar. However, there is not users could be displayed under "Users" in Shadow Session. In fact, another user has been logged in and I could see this user under Citrix Access Management Console --> Citrix Resources --> Presentation Server --> [Server Farm] --> Servers --> [My Server] .

It seems that shadow taskbar can load succesfully without anyerror. But no users could retrieved under Shadow bar. Any advise further ?
Many Thanks.

Sorry, I make a mistake.

After users open an application in Citrix, the shadow option is available.

One more question, how could I enable some users to shadow another users' session, rather than grant them the domain administrators right ??

TKs