private static final String PROTOCOL_VERSION = "1.0"; public static final SimpleChannel INSTANCE = NetworkRegistry.newSimpleChannel(     new ResourceLocation("cosmod", "main"),     () -> PROTOCOL_VERSION,     PROTOCOL_VERSION::equals,     PROTOCOL_VERSION::equals ); I actually have this in a class i don't have to specify i register the simpleimpl anywhere ? 

Post a Git repo of your mod.

It might be any one of the mods you have installed, or a combination of them even. Do you have the same issue with just Forge? You have to take out mods one by one to find the culprit.

Post the debug.log from server and client.

Put the same jars in the mods folder.