java.lang.VerifyError: Bad type on operand stack when posting custom events to the mod event bus

[Julian Vennen]

I'm trying to update the Mod Flywheel from 1.20.1 to 1.20.4 and get the following error message:

java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    net/minecraft/client/Minecraft.handler$zzf000$flywheel$onEndManualResourceReload(ZLnet/minecraft/client/Minecraft$GameLoadCookie;Ljava/lang/Throwable;Lorg/spongepowered/asm/mixin/injection/callback/CallbackInfo;)V @20: invokevirtual
  Reason:
    Type 'com/jozufozu/flywheel/api/event/EndClientResourceReloadEvent' (current frame, stack[1]) is not assignable to 'net/minecraftforge/eventbus/api/Event'

 

This error does not make sense as EndClientResourceReloadEvent extends net.minecraftforge.eventbus.api.Event.

 

Does anyone know what's going on here?

 

Full Logs: https://paste.ee/p/Ae28w
Source code: https://github.com/JulianVennen/Flywheel