Steam has this info modified on hotfix 4 release notes:
NOTICE: Due to a build error causing new crashes, we’ve rolled back Hotfix 4 for the time being. We'll re-release it as soon as we’ve fixed the cause.
If you’ve saved since updating, you won’t be able to load those saves until we’ve re-published Hotfix 4. You can keep playing on your Hotfix 3 saves, you just won't be able to load saves from today’s Hotfix 4 until it’s pushed live again. Sorry about the inconvenience
(8/16/23 @ 3:40pm PDT)
