[2021] My save file isn't appearing in the game.

If the save file does not show in the game's Load menu, then it is not recognised by the game as a valid save file. IOW it is corrupted.

Hard to imagine that mods would do that, but on the other hand this is not a known issue with the game either. Did you have any sort of crash, hang or other problem while playing it?

I think your best shot is to post those saves over in User Mods; hopefully the experienced modders there can see wha the problem in the file it and fix it. Of course if it is too badly corrupted it may be unfixable.

I am sorry that happened to you, whatever the cause!  

My experience is that BSoD are almost always hardware or driver problems. Next time you get one please record the BSoD screen itself, that can help determine the area of the problem.