2.2 doesn't crash but 2.2.1 and 2.3 crashes with Wings mod on startup with "optimizeDataStructures": true
https://www.curseforge.com/minecraft/mc-mods/wings/files/2829351
https://www.curseforge.com/minecraft/mc-mods/llibrary/files/3116493

Modlist:
loliasm-2.3
wings-1.1.6-1.12.2
llibrary-1.7.20-1.12.2
crash-2021-05-08_22.46.50-client.txt

Do you have the full log? It seems like one of the mixins aren't being applied, I also can't reproduce it in any of my modded instances for some reason.

Am using multimc if that matters. Saw it crash from the wings mod on MC Eternal 1.4.3.1 so made a new 1.12.2 forge 2854 instance.
Used multimc "Add instance" for 1.12.2 then edit instance --> version tab --> install forge --> 2584 then added the three mods.

debug.log

[mixin]: Critical problem: mixins.memory.json:ModCandidateMixin target net.minecraftforge.fml.common.discovery.ModCandidate was loaded too early.

I'll launch with Wings+LLibrary in the morning, thanks for the log file.

Ty for trying to fix in 2.3.1. Made new instance, added 2.3.1, added mixinbooter 1.1 and is still getting the crash with wings mod with "optimizeDataStructures": true

Is happily using 2.2 so no need to rush and fix :3

crash-2021-05-11_14.54.30-client.txt
debug.log

It'll be fixed in 2.3.2, I didn't fix it yet since Wings is doing something really unnecessary and still debating how I should fix this if there's another mod doing something similar. I'll close this issue when I fix it!