I have the WarCopter.cs in my oxide/plugins folder when i was in a ftp and uploaded like i did with a few other plugins and after i do this command (oxide.grant user psychopathicwayz WarCopter.cs)    it says permission 'WarCopter.cs' doesnt exist    anyone have this issue ?   tried to message creator and no respond

It's asking you for a permission. Not the name of the plugin. 

oxide.grant user psychopathicwayz PERMISSIONHERE

All permissions are at: warcopter