This code blob seems to raise the following error on line 132, I'm a little unsure how to debug:
Type of expression is ambiguous without more context

       // ANDY: Login with user credentials
        Auth.auth().signIn(withEmail: emailAddress, password: password) { (user, error) in
            // If Successful, pull firstName/lastName
            let ref: DatabaseReference!
            ref = Database.database().reference().child("users").child(emailAddress)

            ref!.observe(DataEventType.value, with: { (snapshot) -> Void in
                // Get user value
                let postDict = snapshot.value as? [String: AnyObject] ?? [:]
                let firstName = postDict["firstName"] as? String ?? ""
                let lastName = postDict["lastName"] as? String ?? ""
                let showroomReference = postDict["showroom"]?["showroomID"] as? String ?? ""

                if showroomReference == ""
                {
                    return completionHandler(.failure(Error.unknownShowroom))
                }

                let remoteUser = try User(record: user, context: DatabaseManager.shared.persistentContainer.newBackgroundContext())

                self.fetchShowroom(forIdentifier: showroomReference) { (result) in
                    do
                    {
                        let showroom = try result.value()
                        remoteUser.showroom = showroom
                        remoteUser.brands = showroom.brands

                        completionHandler(.success(remoteUser))
                    }
                    catch
                    {
                        completionHandler(.failure(error))
                    }
                }
            })
        }