Initial Questions

• I have searched this issue tracker and there is nothing similar already, and this is not on the list of known issues. Posting on a closed issue saying the bug still exists will prompt us to investigate and reopen it once we confirm your report.
• I have verified that this issue occurs in a SUPPORTED environment, meaning I can reproduce this WITHOUT OptiFine, and without Bukkit+Forge server software like KCauldron, Thermos, Crucible, Mohist etc

Mod Version

2.6.0

Describe the Issue

Conflicting Mods

No response

Crash Report

https://gist.github.com/huihiuhuai/1dcd7ac11327a1639f8e7c81f70113ce

Other Details

https://gist.github.com/huihiuhuai/b872a2ce7442343e6d6e92100f056334

I can't fix it, this is on WorldEdit's end to fix.