Direct access to MyChat forum

Hi!
I upgraded to last version.
When I access the forum from the mychat client (Ctrl-F7) everything works fine.
But if I try to access it directly via a shortcut or if I embed a shortcut to another forum post in a new post I get a blank screen (see attachment)
All my users use AD transparent authorisation.
I didnt have this problem with the previous version.
Please help
I upgraded to last version.
When I access the forum from the mychat client (Ctrl-F7) everything works fine.
But if I try to access it directly via a shortcut or if I embed a shortcut to another forum post in a new post I get a blank screen (see attachment)
All my users use AD transparent authorisation.
I didnt have this problem with the previous version.
Please help