Repetitive Last exception error

MHS_2003​  The initialization error is related to broken permissions: the game can't access the user folder.  I see from your screenshots that OneDrive has tried and failed to sync your data, so that may be the problem, as in, OneDrive may be locking up the user folder.  So try the OneDrive-related suggestion here:

[CURRENT ISSUE] Sims 4 already running | EA Forums - 11818313

If that doesn't help, try the antivirus-related suggestion, then the others.  The "already running" error is distinct but shares most of the same underlying causes with the initialization error.

Thank you so much for telling me about the one drive thing, turned it off, and the game started!! But it then crashed so I will try the antivirus thing, 

hopefully it ends up working because formatting my laptop just to play sims will genuinely put me off from ever playing the game :)

edit to add: for some reason, I do not have the virus protection thing… so yeah that sucks.

MHS_2003​  I hope you have some antivirus running, and you should have Windows Defender at least.  Does the game at least start now?  If so, but it's crashing, when does it crash?  If it's before the Main Menu, try removing your saves folder.

If that doesn't help, or the crash is at any other time (and it happens in a new save too), please provide a dxdiag.  Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop.  From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.