There are game issues that require reinstalling it, but a lot more often they're Documents folder problems that have nothing to do with installation. Here's a little guide through them.
RPC → https://lazyduchess.tumblr.com/post/6...
RPCLib → https://lazyduchess.tumblr.com/post/6...
What Caused This → https://www.picknmixmods.com/Sims2/No...
HCDU Plus → https://www.picknmixmods.com/Sims2/No...
4GB Patch → https://ntcore.com/4gb-patch/
Store Content → https://www.tumblr.com/naterxandersim...
Disable OneDrive → https://support.microsoft.com/en-us/o...
I also recommend replacing the exe file to unlink it from EA App for less hassle at launching → http://www.mediafire.com/file/aus7mwe...
💎 Get early access to videos and other perks → / marticore
🟣Discord: / discord
🟤Tumblr: / marticoresims
⚪Twitter: / themarticore
🟠Instagram: / mertikora
🔵Facebook: https://fb.com/themarticore/
🔴Polish channel: / @mertaodsimsow
0:00 Intro/explanation
01:43 The game won't launch
04:20 Is it the Documents folder?
05:30 Mod conflicts
09:44 Crashing: 4GB patch
12:37 Crashing: An object's problem
14:27 Crashing: Broken lots
15:23 OneDrive (and changing Documents directory)
18:50 Outro