Getting a crash when trying to generate a new world:

https://pastebin.com/knYfeSHs

and also

https://pastebin.com/ngMfzgie

I've never seen this issue and it confuses me slightly, as it appears to indicate that the server is not accessible at this stage. Are you experiencing this with just Lootr installed, or only when combined with other mods?

This is part of a modpack. This is the first time I've ever seen this as well and have been running this modpack for months.

https://legacy.curseforge.com/minecraft/modpacks/cosmic-magitech

Can you post the full latest.log for world initialization? I've dug a little deeper into the second report and it appears as though getDataStorage is returning null, in addition to the getCurrentServer hook also returning null. This seems to indicate that there are significant problems with the server state, implying there might be other issues causing the server to be in an error state before it reaches this point.

This will be addresses in the upcoming release for 1.20.0, which adds a vast amount of null checks to ensure that doDecay, etc, never attempt to operate when MinecraftServer or MinecraftServer::overworld are null.