flyugyeom I'm running an older version of macOS than you are, so I don't see exactly the same options in Keychain Access. But this is how to use it (French version); choose your OS at the top of the article to see specifics for your setup.
https://support.apple.com/fr-fr/guide/keychain-access/kyca1083/mac
The crashing issue could definitely be related to your mods or custom content. But it's difficult to say which file in particular might be an issue without testing, although you can compare your list to the one here and remove anything mentioned:
https://www.nraas.net/community/Conflicting-And-Inadvisable-Mods
Other than that, you'll need to test your content manually. Do so in batches or use the 50/50 method:
https://modthesims.info/wiki.php?title=Game_Help:Finding_Problem_Custom_Content#The_50.25_Method