I just encountered the same error for the first time. After reading through this thread I opened up some of my backup files too see if it was just my work scene that got corrupted however they all had the same error. I tried to open a different project altogether and that worked fine which confused me...

Then I noticed that there were files in my backup folder that had a "-beta" extension at the end. After trying out a few i realized that these are all the ones that weren't loading. I never signed up for some sort of beta version of the software so I'm unsure where this is all coming from.

Any help would be greatly appreciated.