Crash issue

[Tocus0637]

So, when I first load up Minecraft, it loads correctly all the mods that I have installed, then, at the third phase of mod loading, when the game is trying to load the Multi Mob Core mod, it crashes.

Here is the crash report
crash-2021-03-16_14.07.09-client.txt

My Optifine version: 1.12.2_HD_U_G5