Interesting, was reading my server log and found this during startup...

[Client thread/FATAL] [base]: Module JEI did not load due to issue: Mod with modid: jei was not found

Interestingly enough, JEI is installed.
Also Interesting to note that the Mod ID for JEI is JEI and not jei, No idea if that matters or not.

JEI: 1.10.2-3.14.5.406
Base: 1.10.2-1.2.3
Forge: 12.18.3.2234
MC: 10.2

Oops that one is fixed in dev, didn't realize it exists in prod

@SkySom have we pushed a new build to fix this?

Nope, I've been trying to wait to release with Content Tweaker, gonna push out a hotfix instead

Fixed in 1.3 (On curse already)