the game always crashed when i tried to launch carpet mod with optifabric+optifine in 1.15, carpet ver: 1.4.27, optifabric ver:1.0.1, optifine: G6. here's the crash report:
Optifabric is still using the traditional Early Riser initialisation
at net.fabricmc.loader.entrypoint.EntrypointContainerImpl.getEntrypoint(EntrypointContainerImpl.java:37)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke0(EntrypointUtils.java:50)
at net.fabricmc.loader.entrypoint.minecraft.hooks.EntrypointUtils.invoke(EntrypointUtils.java:36)
at net.fabricmc.loader.launch.knot.Knot.init(Knot.java:137)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:27)
Caused by: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 9 path $
at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1559)
at com.google.gson.stream.JsonReader.checkLenient(JsonReader.java:1401)
at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:542)
at com.google.gson.stream.JsonReader.peek(JsonReader.java:425)
at com.google.gson.JsonParser.parse(JsonParser.java:60)
... 31 more

Found existing patched optifine jar, using that

[18:20:25] [main/WARN]: Error loading class: shadersmod/client/ShadersRender (java.lang.ClassNotFoundException: shadersmod/client/ShadersRender)

Exception in thread "main" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:228)
at net.fabricmc.loader.launch.knot.Knot.init(Knot.java:139)
at net.fabricmc.loader.launch.knot.KnotClient.main(KnotClient.java:27)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at net.fabricmc.loader.game.MinecraftGameProvider.launch(MinecraftGameProvider.java:226)
... 2 more
Caused by: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:363)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:208)
at org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClassBytes(MixinTransformer.java:178)
at org.spongepowered.asm.mixin.transformer.FabricMixinTransformerProxy.transformClassBytes(FabricMixinTransformerProxy.java:23)
at net.fabricmc.loader.launch.knot.KnotClassDelegate.getPostMixinClassByteArray(KnotClassDelegate.java:157)
at net.fabricmc.loader.launch.knot.KnotClassLoader.loadClass(KnotClassLoader.java:150)
at java.lang.ClassLoader.loadClass(Unknown Source)
at net.optifine.reflect.Reflector.(Reflector.java:302)
at net.minecraft.class_128.method_559(class_128.java:101)
at net.minecraft.class_128.(class_128.java:54)
at net.minecraft.class_128.method_24305(class_128.java:414)
at net.minecraft.client.main.Main.main(Main.java:129)
... 7 more

Caused by: org.spongepowered.asm.mixin.injection.throwables.InjectionError: Critical injection failure: Variable modifier method changeTickPhase(F)F in carpet.mixins.json:WorldRenderer_pausedShakeMixin failed injection check, (0/1) succeeded. Scanned 1 target(s). Using refmap fabric-carpet-refmap.json
at org.spongepowered.asm.mixin.injection.struct.InjectionInfo.postInject(InjectionInfo.java:408)
at org.spongepowered.asm.mixin.transformer.MixinTargetContext.applyInjections(MixinTargetContext.java:1291)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyInjections(MixinApplicatorStandard.java:1042)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.applyMixin(MixinApplicatorStandard.java:395)
at org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:320)
at org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:345)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:569)
at org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:351)
... 18 more

this is the error related to optifabric and optifine when i tried to launch the game.

Well, problem is here again: 1.19.3 OptiFabric Beta with gnembons Carpet-Mod version 1.4.96.

This is the same issue as gnembon/fabric-carpet#605, it has been fixed for 1.16.x but backporting it is a big pain