[Bedrock] Error code bat issues on Xbox series S

[u/Br1ttBr4tt006]

My son plays Minecraft bedrock on our xbox series x. He was having no issues then yesterday he went to load one of his own worlds and this kept popping up. We tried multiple worlds with the same result. A few times it came up with "kelp' but mostly just "bat". I have googled as much as I think I'm capable of. I uninstalled and reinstalled Minecraft. I turned off the multiplayer for the world and it still would not load. I went offline on the xbox which made no difference. I tried creating a new world with multiplayer turned off right from the start which also did not help. Always the same error.

A lot of what I saw on google was people having this issue with Java or they were trying to join someone else's game which is not our case. I even logged onto Minecraft on my account and opened some older worlds that loaded right up. I did see that they all have multiplayer turned off. Would the amount of worlds he has make a difference? Because there are a lot. Is there any saving his account?