https://pastebin.com/RsEGZ1Na
SGCraft-1.20.0.jar

Crashes before actually loading.

What else are you using that utilizes mixin?

Besides your mod it seems nothing else. I tried to search the log for MixinBootstrap without anything coming up and tried Mixin and still nothing without your new version or the sponge version you had before.

This on pure forge no sponge of course.

That's impossible because your error indicates that you have something already loading mixin, which is an earlier version that 0.7.11.

@KaneHart Give a full log instead.

https://pastebin.com/jBVNAAvq
Sorry about that this the full log.

[18:53:30] [main/INFO] [mixin]: SpongePowered MIXIN Subsystem Version=0.7.4 Source=file:/C:/Users/kanec/Documents/Curse/Minecraft/Instances/The%20Next%20Leap/mods/malisiscore-1.12.2-6.4.0.jar Service=LaunchWrapper Env=CLIENT

Hehe, malisiscore! That's it.

Use this build of Malisis to solve your issue.

https://ore.spongepowered.org/Dockter/MalisisCore

Uh, that build does not exist on curseforge unfortunately.

So what, download it anyways.

You must not know the new terms but Curse does not allow that anymore. The only way you can use a repeated mod like that is to publish on curse then add the original mod author to it with permissions sadly.

Either way it's the other mods at fault ish and both for anything sponge haha.