[MC-197934] No key layers in MapLike[{}]; No key structures in MapLike[{}]; Not a registry ops

Java version :

openjdk version "1.8.0_262"
OpenJDK Runtime Environment (build 1.8.0_262-b10)
OpenJDK 64-Bit Server VM (build 25.262-b10, mixed mode)

I recently updated a minecraft server from 1.15.2 to 1.16.2. I get this error message every time the server starts (before "preparing level" starts):

[main/ERROR]: No key layers in MapLike[{}]; No key structures in MapLike[{}]; Not a registry ops

The world is a superflat/void, so I don't see any issue with the terrain generator. I doesn't seem to affect anything so far.

Comments 4

MinePro120 2020-08-13T21:59:27Z

I found something! If the "level-type" is set to default (instead of "flat" that it was before) the message disappears. Is this expected behaviour though?

MinePro120 2020-08-13T22:09:33Z

Back when I created the server, I copied the world from singleplayer and set "leve-type" to "flat". I think, due to bug MC-134900, I wasn't given any error then (my "generator-settings" has always been blank) but now I am. Am I right? If that's the case, I should close this issue.

MinePro120 2020-10-05T18:27:38Z

Setting level-type to default solved the issue. It wasn't an issue after all, just that in previous version of minecraft I didn't get any erros for my wrong generator-settings.

MinePro120 2020-10-17T17:53:30Z

This should be marked as solved.