Warum bekomme ich diesen Fehler EXC_BAD_INSTRUCTION (Code = EXC_I386_INVOP, Subcode = 0x0)

Question

Kann mir bitte jemand helfen und mir sagen, warum bekomme ich Fehler in Zeile 2?
Meldungsfeld sagt auch:

SignIn fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)

@IBAction func done(sender: UIBarButtonItem) { 

    if isSignIn == false { 

     //Register code 

     //Checking for empty boxes 

     if self.username.text == "" || self.password.text == "" || self.riderDriverSelect.selectedSegmentIndex == -1 { 

      //Red Border color for missing fields 


      if self.username.text == "" { 
       self.username.layer.borderColor = UIColor.redColor().CGColor 
       self.username.layer.borderWidth = 1.0 
      } 

      if self.password.text == "" { 
       self.password.layer.borderColor = UIColor.redColor().CGColor 
       self.password.layer.borderWidth = 1.0 
      } 

      if self.riderDriverSelect.selectedSegmentIndex == -1 { 
       self.riderDriverSelect.layer.borderColor = UIColor.redColor().CGColor 
       self.riderDriverSelect.layer.borderWidth = 1.0 

       self.showAlert("Missing field required", message: "Fill in or select missing fields in red") 
      } 


     }else{ 

Answer 1

hatte 1 string zwei Bool, und beide der Bool waren! musste isSignIn Bool wechseln? das hat das Problem behoben

var buttonTitlePressed: String? var isSignIn: Bool? var isUser: Bool!