Sims 4 infinite Loading Screen

l0calsassym1ssy​  Please rename the Mods folder, to keep the game from loading its contents, and see whether it helps.  If it does, then you know where to look for the issue.  If it doesn't, we can see whether OneDrive is causing problems or there's something else on your system that should be addressed.

The mods folder in one drive?

l0calsassym1ssy​  Yes.

I've only just been able to get on but the documents folder in my one drive takes me to the one on my laptop (not my old one)

I repaired the game, deleted duplicate files and I can now get into my save game but still can't get into CAS from within my save

l0calsassym1ssy​  Did you rename the Mods folder?  The point here is to test without mods or custom content.  Renaming the folder prevents the game from loading it without actually deleting the folder, and without letting OneDrive redownload a duplicate copy of the folder like it might if you removed it.

There is no duplicate, there's a documents shortcut and it takes me to the documents on my laptop. There's only one mods folder, which is why I'm confused 

l0calsassym1ssy​  I didn't say there was a duplicate.  I said if you remove the Mods folder instead of renaming it, you might get a duplicate.  I also said if you rename the Mods folder, your mods won't load.  So please do that, and let me know how it goes.