Using this mod with Optifine on a 1.20.1 server and it crashes when a player takes a buried treasure map in their inventory

I recreated the issue multiple times in single-player after having it happen in my multiplayer server, the only way the player could join without crashing was to /clear their inventory every other player in the server wasn't affected otherwise.

I reported to Optifine originally and was directed to alert you before reporting the issue with Optifine.

All otpifine issues are inherently optifine fault. This is no difference. Optifine is inherently incompatible with mods as it makes changes to the base code in a non compatible way. There's no reason at all why anybody should ever be using otpifine, has always been a pain to deal, completely disregarding the missing environment ifter being outright incompatible with forge itself (like in all 1.19) with and all it does can be done by other actual mods but better