Yes it's not uncommon that when deleting a part, (or smart part) to have a crash when there is no very complicated modification. (3-4x per month but much less than at one time since I've been in 2019) After that, on my side, I only work in Pack & Go, so in a way the copy of the copy of the copy.
It often happened to me under Creo (yes I know, not the same software all this)
This came from pieces that had been created in a biiiiiiien version prior to the reading version. There were three solutions to this:
Take your courage in both hands and rebuild everything yourself
Opening again and again while praying that it would eventually pass. Sometimes, on a misunderstanding it was good (practical on days when you don't want to work. It gives the impression of ^^)
Open each part of the assembly individually to make them pass into the new version of the software, check that there are no problems in the part and then save them. Once this is done, look at the constraints of your assembly if there is no conflict
Solution 2) seems to have worked in your case, so much the better I would still advise you to do a reconstruction in a new assembly. Indeed, if the problem has passed "by magic" it can just as easily come back in the same way