Get server Crash with the latest Recurrent Complex 1.4.8
https://pastebin.com/Xj6Dh3KE

Client loads fine

Minecraft Version 1.12.2
Forge Version: 2768

Seems like its caused by Recurrent Complex calling net/minecraft/client/gui/GuiScreen, which did not occur in version 1.4.7. Falling back seemed to work on servers just fine, so just do that for now until its fixed.

Oh god damnit, this happens every time I update.
Thanks for reporting :)