when you download a file that has an assembly,it has bolts nuts washers or pins.Now when you open the assembly there is a red question mark on some components and Inventor asks that you resolve the file" What is the procedure of resolving the components that have the question mark(?) (Unresolved)
This means that files are missing deposit models.
The submission was poorly exported.
I agree with Tomek the user may have neglected to do a ”pack-n-go” when exporting.