I'm Done With Alpha 21.2 & Returning To Alpha 20.7

Originally posted by Orca MS15LF:

Originally posted by 8_Hussars: Have you verified your game files and mod integrations?

I need the A21 optimizations to really enjoy the game. For the other stuff, opinions differ but we are all welcome to our own.

Its nice the TFPs allow access to previous versions, right?

Here's a video of that Fetch challenge that is glitched. It shows when I interact with the yellow marker at the beginning, I get a load of text crap on my screen, then it shows no location on the compass where the leather bag is and it only tell me where to go where that yellow marker was when I had already interacted with it. Then I show three leather bags where the package should be in one of them and nothing shows. Even when I later went to another Trader to start a challenge hoping it would overwrite this glitched one, I was sent to the same location from another Trader. What a load of crap.

https://www.youtube.com/watch?v=UgGpVRo2Zi8&ab_channel=ORCAMS15LF

That error indicates incorrect data. Either corrupted client data, incompatible mods, or the save is from an earlier unstable build. A log might show better information towards narrowing down the cause, but the basics of excluding the client and save folders from security software, and then validating the files a few times might get you running again.
Also note that if you had a20.x world data when you were making your maps for a21, the new maps are very likely to end up corrupted if you use the same or similar seed and it re-uses the same world name. There is a reason you are strongly advised to wipe all previous data before starting the new major build.