My instance crashes within seconds after updating from 4.1-hf to 5.2-hf2
I made sure that the old config folder was deleted.

debug

latest

mod list

Is your version of mixinbooter up to date?

This one?
https://www.curseforge.com/minecraft/mc-mods/mixin-booter

It is:

However my MixinBootstrap isnt because the latest version, 1.1.0, has always crashed my instance in a similar manner. So I'm still running 1.0.5

See if this mod helps, which may also allow you to update MixinBootstrap

No, same crash. It makes no sense.

debug

latest

I'm going to have to dedicate an hour or two trying mod combinations because I even used the older MixinBootstrap, 1.0.5, for another instance and it didnt crash.

So far that combination was good so I'm actually lost right now.

Bingo
Crashed when I added Sledgehammer.

Uh, I'm going to have to check my options because I do make use of it.

You may want to post an issue to sledgehammer. Ill leave this issue open for now until there is some more information, but I do not think the problem is stemming from Music Triggers. It's likely some mixin compatibility issue

Ok I actually did some more testing and it seems like it does crash with only Music Triggers, MixinBooter, and Sledgehammer installed. I will do some more testing and see if it is something fixable from my end

I figured out the problem and it will be fixed in 5.3

Fixed in 5.3