I can't tell you more than the title does.

I'm trying to put this mod in a modpack and it's crashing before it launches with Create mixins or something like that.

Is this with Tomes 1.0 or 1.1? if 1.0, update the mod and try again just in case. If it still doesn't work, I'd like the full crash log.

It's with the lastest version you uploaded, but I also tried with the first one.

Here you have the crash log:
crash-2021-10-12_11.54.05-fml.txt

Seems to be a problem with the Survive mod as far as I can tell. I'm getting in contact with their dev so hopefully I can work this out soon.

I've completely rewritten the conflicting code out, give it a try! https://www.curseforge.com/minecraft/mc-mods/tomes/files/3490683