It is only returning the attributes. To set your own attributes change the "MobEntity.setCustomAttributes().create()" to YourEntityClass.func_234188_eI_().create(). I would recommend to rename "func_234188_eI_" to "setCustomAttributes" or something similar though
I think this is caused by the fact that you did not create the cows attributes. In your main class cunstructor do:
// Register the setup method for modloading
bus.addListener(this::setup);
and add the method:
private void setup (final FMLCommonSetupEvent event)
{
event.enqueueWork(() -> {
GlobalEntityTypeAttributes.put(ModEntityTypes.GS_COW.get(), MobEntity.setCustomAttributes().create()
}
}
I believe the ModId in mods.toml and in your main mod class arent matching. Are you sure that your @Mod(...) tag in your main mod class contains the correct ModId?
minecraft 'net.minecraftforge:forge:...'
under dependencies in build.gradle
and if you are using intellij, there should be a gradle panel. Select it and there should be a refresh button, or when you made changes to the build.gradle file a small window will pop up and asks you if you want to reimport the gradle project.