[1.12] EnderIO (Modular Install) and this mod = Crash.

[MagmaSlime123]

Forge 2854.

latest.log

crash-2020-08-13_11.27.17-client.txt

[LemADEC]

This is vanilla limit for 4096 block ids, it's unrelated to EnderIO and this mod. You can have so many mods in the same modpack. Consider using Caliper to evaluate which mods are consuming the most ids and remove them accordingly.

[MagmaSlime123]

JEIDs refuses to work for me for some reason.

[LemADEC]

JEIDs add more problems than it solves. You need to remove redundant mods or ones you're not playing with.
Some mods can also be configured to remove unused decorative blocks.