Alright. There's a limited amount to what I can do due to the fact that the saves that DO load don't have anything glaringly wrong in the save file, and the saves that DONT load don't give a crash log, and they're also unable to be opened in my save editor. I did, however, take one of the saves that I was able to load into and deleted all the player entities. If I had to guess, it's either something player related in the save file, something software related on your end with the installation of Satisfactory, or an incorrect build version. Give this save a shot (with all players deleted) and see if it'll load you in:
http://s000.tinyupload.com/?file_id=03850288403354614633 - If not, you'll probably have to wait until a dev chimes in, which I know they will as soon as they have a better answer.