NSGenericException', reason: 'Unable to install constraint on view

Question

Terminating app due to uncaught exception \'NSGenericException\'

Terminating app due to uncaught exception \'NSGenericException\', reason: \'Unable to

Answer 1

I got this problem using a UIPickerView like input of a UITextField (using Autolayout). When I push another viewController and thus a pop it to the viewController with the picker, the app crashes. I found the following solution, in the UIPickerViewController:

-(void)viewWillAppear:(BOOL)animated{

    [self.pickerView removeFromSuperview];
    [self.pickerView setTranslateAutoresizingMaskIntoContraints:YES];
    [self.view addSubview];

}   

You can also set the UIPickerViewPosition after removing from superview. I hope that can help you!