kattieisadino You can still elect to play Sims 4 with missing packs. If you don't care about the missing content, just go right ahead.
For Sims 3, Bridgeport comes with the Late Night expansion, which is part of EA Play. Have you ever bought LN separately, or did you only ever access it through a subscription? Removing an expansion from an ongoing Sims 3 save does corrupt the save, so I would avoid doing that until LN is restored, or else start new saves instead.
If you're seeing the "serious error," that's a known issue usually but not always connected to OneDrive. Please see the first post of this master thread:
[Current Issue] Sims 3 "serious error" when loading save | EA Forums - 8322938