libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

Answer 1

In my case, it was XCode getting tired and failing to start app with this message, due to an assertion failing (that was set by our code).

Running on another device showed the assertion failure, which we were able to fix, and everything went back to normal.

Answer 2

In Xcode 9 and Swift 4:

Print exception stack to know the reason of the exception:

1. Go to show break point navigator.

2. Add (+) Add Exception Breakpoint.

3. Select the new breakpoint, Control-Click, Edit Breakpoint.

4. Add Action and Enter: po $arg1

Answer 3

In my case, I was calling a delegate method but the method wasn't declared.

This error is generic and can appear by a number of reasons. Make sure you have not disabled your Logs to actually see what happened. Enable OS_ACTIVITY_MODE in the schemes if you have disabled it. You might have disabled it to prevent a lot of irrelevant logs but they are handy.

You can also trace the cause in more details by adding an exception breakpoint po $arg1. As already mentioned by Ahmed-Lotfi

Here is a common checklist that you can go through.

2) Check if you have renamed an IBOutlet and calling it
3) Check if you have renamed a method name or the method doesn't exist
4) Check if you are trying to add or remove any view from hierarchy
5) Check for any missing framework or library
6) Check if you’ve forgot to register your custom cell identifier
7) Check for any missing flag in the Proejct Setting (-obj) or any other linker flag etc.

Answer 4

there may be more than 1 IBAction for a button in your view controller try finding out those and removing all previous item for that button in your controller and create new button .It will solve your problem.

Answer 5

I had this same error when I had a typo for one of the views while building constraints using the visual formatter. I hope that helps someone... or me again one day.

Answer 6

My situation was a little different, I was trying to segue into a UINavigationController, and what fixed it for me was getting the main queue portion.

For Objective-C:

dispatch_async(dispatch_get_main_queue(), ^{
    [self performSegueWithIdentifier:@"SegueName" sender:self];
});

For Swift 3:

DispatchQueue.main.async { [weak self] in
    self?.performSegue(withIdentifier: "SegueName", sender: self)
}