This mod allows players to create and remotely control Avatars. Avatars act like players, with a few minor exceptions. The mod also includes a few custom entities to control and create the Avatars.
Look at picture, too lazy to type many words.
Ok, that's definitely a compatibility issue with another mod. I've added a nil check there, but since I don't know what other mods you have or the situation you were in, I can't verify the fix.