P3D 3.3.5 won't display after load

Had this problem before but can't remember the fix..

When I start P3D I see the splash screen. Then I see something loading and then the splash screen goes away and I can't open P3D. The program is still running according to task manager but I can't ope or activate it.

Tried a fresh DLL.xml and config but that won't help.

***EDIT***

My god... How can I forget to update FSUIPC after installing a sim update....