I can't test my mod.

Whenever I try to load my mod it just either doesn't even launch Minecraft or it says this: "Cannot invoke 'java.lang.Class.getName()' because 'this.modClass' is null."

Here's what it looks like:

I'm also getting the message "Cowardly refusing to send event net.minecraftforge.client.event.EntityRenderersEvent$CreateSkullModels to a broken mod state."