On this line both mod IDs need to be lowercased. OpenBlocks is available for 1.12.2, and Ender IO is in a pre-alpha testing state and is under heavy development to modularize it. My tests with Ender IO caused a crash relating to the above.

Hello,
You are looking at the wrong branch there. The names have been lowercased since the mod was made for 1.12.
https://github.com/vadis365/Mob-Grinding-Utils/blob/MC1.12/MobGrindingUtils/MobGrindingUtils/src/main/java/mob_grinding_utils/MobGrindingUtils.java#L79
Cheers,
Me.