I have a part, that I unfortunately can't share with you. It has 2 configurations (TOP and BOTTOM). I can open the TOP config with no problem. If I switch to the BOTTOM config, the feature tree fails early on and the whole thing blows up (there is still a solid body, but missing most features below the first failure). When I look at the feature that fails first, there doesn't appear to be anything wrong or anything about the features that would make me think it might not solve. If I try to change back to the TOP config, the feature tree fall apart in the same location. I can only get it to solve by closing without saving and reopening. 

I can open an assembly that has both parts in it and the TOP will be present, but the BOTTOM fails the same way as when I open it individually. 

These files are saved to a network drive and I can open them without issue on a coworkers computer!

I've restarted my PC a handful of times and the problem persists for me... is there some way of clearing a cache or something.... I'm totally stumped as to why I have been working with this part for a week without issues, I crashed Solidworks somehow just making a sketch... and now my PC can't solve this part!