Describe the bug
Game crashes on startup, looks like Iceberg uses something the mod also tries to use:

[19:05:19] [main/INFO]: Mixing LivingEntityMixin from iceberg.mixins.json into net.minecraft.class_1309
[19:05:19] [main/ERROR]: Mixin apply for mod things failed things.mixins.json:LivingEntityMixin -> net.minecraft.class_1309: org.spongepowered.asm.mixin.injection.throwables.InvalidInjectionException Variable modifier target for net/minecraft/class_1309::waxGlandWater was removed by another injector [INJECT Applicator Phase -> things.mixins.json:LivingEntityMixin -> Apply Injections -> -> Inject -> things.mixins.json:LivingEntityMixin->@ModifyVariable::waxGlandWater(F)F from mod things]
org.spongepowered.asm.mixin.injection.throwables.InvalidInjectionException: Variable modifier target for net/minecraft/class_1309::waxGlandWater was removed by another injector [INJECT Applicator Phase -> things.mixins.json:LivingEntityMixin -> Apply Injections -> -> Inject -> things.mixins.json:LivingEntityMixin->@ModifyVariable::waxGlandWater(F)F from mod things]
at org.spongepowered.asm.mixin.injection.modify.ModifyVariableInjector.inject(ModifyVariableInjector.java:169) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.injection.code.Injector.inject(Injector.java:276) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.inject(InjectionInfo.java:445) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinTargetContext.applyInjections(MixinTargetContext.java:1374) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyInjections(MixinApplicatorStandard.java:1052) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:400) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:325) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.TargetClassContext.apply(TargetClassContext.java:421) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:403) ~[sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:363) [sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:234) [sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:202) [sponge-mixin-0.10.7+mixin.0.8.4.jar:0.10.7+mixin.0.8.4]
at meteordevelopment.meteorclient.asm.Asm$Transformer.transformClassBytes(Asm.java:102) [meteor-client-0.4.8-1415.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:247) [fabric-loader-0.12.12.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:150) [fabric-loader-0.12.12.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:155) [fabric-loader-0.12.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?]
at java.lang.ClassLoader.defineClass1(Native Method) [?:?]
at java.lang.ClassLoader.defineClass(ClassLoader.java:1012) [?:?]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:150) [?:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.defineClassFwd(KnotClassLoader.java:218) [fabric-loader-0.12.12.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassDelegate.tryLoadClass(KnotClassDelegate.java:174) [fabric-loader-0.12.12.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:155) [fabric-loader-0.12.12.jar:?]
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) [?:?]
at vazkii.patchouli.client.handler.BookCrashHandler.appendToCrashReport(BookCrashHandler.java:23) [Patchouli-1.18-60-FABRIC.jar:?]
at net.minecraft.class_6396.handler$cmk000$patchouli_addContext(class_6396.java:1016) [client-intermediary.jar:?]
at net.minecraft.class_6396.(class_6396.java:57) [client-intermediary.jar:?]
at net.minecraft.class_128.(class_128.java:32) [client-intermediary.jar:?]
at net.minecraft.class_128.method_24305(class_128.java:272) [client-intermediary.jar:?]
at net.minecraft.client.main.Main.main(Main.java:153) [client-intermediary.jar:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?]
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?]
at net.fabricmc.loader.impl.game.minecraft.MinecraftGameProvider.launch(MinecraftGameProvider.java:608) [fabric-loader-0.12.12.jar:?]
at net.fabricmc.loader.impl.launch.knot.Knot.launch(Knot.java:77) [fabric-loader-0.12.12.jar:?]
at net.fabricmc.loader.impl.launch.knot.KnotClient.main(KnotClient.java:23) [fabric-loader-0.12.12.jar:?]
[19:05:19] [main/ERROR]: Minecraft has crashed!

@AryonLegacy I believe Iceberg is unrelated to this crash, since it does not remove any variables as the error message indicates. Could you post the full log please?

You might be right, il test later to confirm

Closing this due to inactivity. I believe Iceberg is unrelated.