Once I made the stupid upgrade from windows 8 to windows 8.1 I realiced that Autodesk Inventor wasn`t compatible with it (windows 8.1)
So, I backed up all my Inventor files and then my PC was downgrade to windows 8 again.
What I noticed is that many, if not all of my assemblies show a lovely ? symbol and says that it is unresolved.
What do I`ve to do to solve this issue?
Thank you in advance for your attention and possible help.
I have never faced something similar but I think I have something in my mind...
Start a new project and copy all the files from an existing one. Then try to open an assembly file (from the new project).
If you didn't try this yet I believe that it worth to give a try.
My opinion is that somehow your projects have been affected.