Originally Posted by Cindercrown
I cannot load any save games after Patch 5 when I have uninstalled all mods. I uninstalled, because I suspected my mods to cause a different bug.
The game warns me that loading the save without the mods might make the game unstable, but offers me to load anyway. If I choose “Yes” nothing happens. “No” does nothing either. This is true for all saves I used a mod with.

So basically, Larian managed to break their own game once more. Congrats. I'm actually impressed.
Patch 5 broke the game's ability to load any modded save that has had any mods removed. It is... unfortunate. There is a workaround posted on Nexus mods for now. It seems to work for some people: https://www.nexusmods.com/baldursgate3/mods/4767?tab=description