I wanted to use the DIRECT command to snap a face to another.
I did this working in an assembly, by edit part, than DIRECT.
I received a warning that i couldn't DIRECT the face in a dialogbox. I clicked cancel to close the warning dialogbox.
After this, i couldn't do anything anymore in the assembly. The only thing that worked was my 3D Pilotmouse, so i was able to turn arround the assembly, but couldn't click any commands anymore, even not saving my assembly.
The only thing i could do was closing Inventor with CTRL+ALT+DEL
This is not the first time this happened.