I’m playing the Enigmatica 2 modpack, for Minecraft 1.12.2, and I experienced a low frame rate, major frame rate dips causing the game to essentially freeze for about a second each time, and actual game freezes roughly every 10 minutes, causing the game to completely freeze for 10–20 seconds at a time, sometimes crashing. The issues happened in both singleplayer and multiplayer. My performance improved upon removing MalisisDoors and MalisisCore.

I don’t have any MalisisDoors blocks or items in my world, and the base has no vanilla doors, so it seems as though MalisisDoors and/or MalisisCore is causing performance issues even when none of the mod’s features are actively in use in the world.

I’m not 100% sure whether the game freezes and crashes were caused by MalisisCore and/or MalisisDoors, as those started happening much less frequently once I allocated more RAM, but I did get a much better frame rate upon removing these two mods.

Modpack version: 1.62 (latest version as of today)
MalisisDoors version: 7.3.0 (latest version as of today)
MalisisCore version: 6.5.1 (latest version as of today)

Before removing MalisisDoors and MalisisCore:

After removing MalisisDoors and MalisisCore:

The only differences between these two tests is that MalisisCore and MalisisDoors were removed in the second test.