*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key emailField.'
My project is on Xcode 9, using Swift 4 and firebase... I'm sorry for the way I'm asking but i don't really know how to go about asking this.
I think you not connected the IBOutlet for the emailField in Storyboard properly. Not connected or multiconnected.