Compile the following template. Fields marked with (*) are mandatory, Fields with (-) are optional, Fields with (!) are mandatory in case of crash or bug

Type of Issue/Request (Bug / Crash / Suggestion / Translation / ...):

(*)
Bug

Version of the mod or build number:

(*)
extraalchemy-0.3.8.6.1-release

Are you a Single Player, a Multiplayer Client (You are a player in a server) or Server Side?:

(*)
Server Side

Minecraft Version (1.9.4, 1.10, 1.10.2, 1.11.2...):

(*)
1.12.2

Description (or what were you doing when it crashed):

(*)
Server saving chunks, this trace was from logging in while a special mod is running on the server to find this problem.

Pastebin of the log (fml-client-latest.log from your instance/logs folder):

(!)
https://gist.github.com/ProsperCraft/5d552827c6a30b87051073bbfb71ad72
ancienttowncraftlogs.zip

I started the investigation because I kept getting this- even when there were no players on-
https://gist.github.com/Potato-bot/47f3b6e6d3d4be8f33018a2a7ba31e5d

ModPack (or list of mods via Pastebin. If using a modified modpack, write BOTH the modpack AND the link to the full mod list):

(!)
https://minecraft.curseforge.com/projects/ancient-towncraft/

Pastebin of the config file (extraalchemy.cfg from your instance/config folder):

(!)
https://gist.github.com/ProsperCraft/a52387ff33440191141a0178997ebceb

OS and Java version (Java8 + Windows10 / Java7 + MacOS / ...):

(!)
openjdk version "1.8.0_191"

Other information that you think might be useful:

(-)

News?

I removed it from the pack, which stopped the crashing.

Backup your world, remove extra alchemy, start and stop your server. Does it still crash?