-Cannot add tags.
-Cannot remove anything.
-Rendering is broken:

Pressing expand crashes the client:
https://gist.github.com/Darkere/90d0b8f6e526f3d54de8de2310c13e7a

Forge 1.16.3 34.1.23
Rftools base: rftoolsbase-1.16-2.0.5.jar

I can reproduce. Testing now

Should be fixed now. Releasing updates at this moment