I was trying to make a modpack on the twitch launcher, and IE was a part of it. However, every time I tried to start it, it crashed during the initial startup. Here is the crash report Even with just IE and forge it gave the same crash

IELoadingPlugin (ImmersiveEngineering-0.12-79-core.jar)

outdated "core" files are not removed automatically, so you have to remiove the outdated file i noted here

this is a bug with forge and nothing that can be done about it, because forge forbids to remove those file on launch and it has to be bundled with the mod-jar file and gets extracted automatically by forge

I was trying to make a modpack on the twitch launcher

also from your issue it looks like you updated some parts of the modpack on your very own, which can indeed produce other trouble as some mods can't deal with heavily changed configs when they need to add new stuff

You might want to try using a slightly older forge version (2655). 2656 contains some potentially broken/breaking changes.

This is a Forge issue, all capabilities are being initialized to null in the latest forge version. I'm debugging this right now, see the Actually Additions issue I linked above for future updates.