Minecraft version & Mod Version:
Minecraft 1.12.2
RootsClassic-1.12.2-1.1.7
I couldn't figure out which mod conflicts with rootsclassic, but rootsclassic have tested with optifine/vanillafix/foamfix/betterhud etc.(two-mods combination), without any lag.

Single player or Server:
Single player

Describe problem (what you were doing / what happened):
Recently, when I wear even only one piece of rootsclassic's armors (either sylvan or wildwood), fps drops from 60 to 50 and then freeze to 0 in one minute.

Crash log (if any):
Too laggy that crashing freezes itself !
(Well, please forgive my not-so-good english.)

1. 1.12 is lo longer supported unless it's a critical bug
2. Optifine is not supported so reproduce it without

Electroblob77/Wizardry#763

Emm, I have to set EBwizardry's animation off, or there's no method to solve the problem =(