"No key position_predicate in MapLike" upon server connect followed closely by crash

Please attach the server.properties, if possible before you ran 1.16.

unfortunately, I didn't have the presence of mind to fully backup the server before updating to 1.16

I've attached the crash reports and my current server.properties

Were you using the Buffet world generation feature in 1.15, or how was the world generated exactly?

It was generated as a realm then downloaded and converted to a server, as far as I know, all the world generations settings were standard

Java 11 is not supported, please check if this is an issue with Java 8.

I am running Java 8 and have the same issue with the almost the same exact error messages (the only difference is that the probability value is 0.1f instead of 0.2f). I can restart the server but it halts again with the same issue soon after. My server.properties is the same except for name and motd, and flying is enabled and command blocks are enabled.

The weird part is that the server was fine for about 9 hours as well before this happened, and there wasn't any obvious trigger. We (5 people) were all just doing normal stuff, placing blocks or exploring. No command shenanigans or anything.

This issue relates to the specific crash, which may be a different manifestation of MC-63590 for Java 11 - the console spam is tracked in MC-191388.

after updating to 1.16.1 the server was stable for a while but unfortunately, the issue has returned and whenever I connect to the server I get the console spam them the server stops itself.

I've attached the crash reports below