The crash has been fixed as of 4.00 Beta 9.
All crashes with 4.0 beta, on the same playthrough.
Crashed to Desktop while reloading a quicksave
Crashed to desktop while reloading a save game while in a game
Crash while quitting to desktop.
Another case triggering this crash was identified and will be fixed in the next beta (expected to be called 4.0 Beta 9 at the time of writing this). A workaround to prevent the crash is also provided in the description.