doesn't work in 21w15a Snapshot

[codemonkey76]

I get the generic
ERROR
Game crashed
An unexpected issue occurred and the game has crashed. We're sorry for the inconvenience.
Exit code: 0

[altrisi]

Code has been pushed for 21w18a, may work in newer versions. You can get the development builds from the artifacts in the last Github Actions run (the jar without -dev or -sources suffix).