Component failed (missing model) on downloaded parts
I am making an assembly using parts downloaded from the PTC manufacturer CAD portal, with the exception of a mounting plate part that I created. After assembling and constraining everything, I save and exit with no issues. But when I try to open the file, the only part left is my mounting plate and all of the downloaded parts are red in the model tree and in the regeneration manager they all say "component failed (missing model)". Not sure what issue is; everything seems to be in the right place, but I'll admit I'm not computer savvy at all so maybe I'm missing something. I've redone this assembly so many times and it is driving me up the wall 

