Every time I try to enter the menu to create a custom superflat world the game crashes. It happens only if, and if only twekeroo is enabled. I'll attach the crash report
crash-2020-11-25_20.59.17-client.txt

This should be fixed in the 2020-11-10 build.

https://www.curseforge.com/minecraft/mc-mods/tweakeroo/files/3107606

Oh your right, i thought i had most up to date version already. Well thanks