# Thread 1: signal SIGABRT (app crashes with "libc++abi: terminating")

**Code:** `SIGABRT` · **Category:** iOS · **Seen on:** iOS

The app deliberately aborted — an uncaught exception, failed assertion or fatalError. The console above the crash has the real message.

## Meaning

SIGABRT is the symptom. Common causes: unconnected IBOutlets (NSUnknownKeyException), storyboard/identifier mistakes, missing Info.plist privacy strings, force casts, or NSInvalidArgumentException from unrecognized selectors. Add an Exception Breakpoint to stop where it’s thrown.

## Common causes

- Uncaught Objective-C exception (NSUnknownKeyException, NSInvalidArgumentException)
- Storyboard/XIB outlet or identifier mismatch
- Missing usage description in Info.plist
- fatalError / precondition failure

## Quick fix

1. Read the console output above “libc++abi: terminating”
2. Add an Exception Breakpoint (Breakpoint navigator → + → Exception Breakpoint)
3. Fix the outlet/identifier/plist entry named in the message

## Detailed fix by platform

### Xcode

1. `# Breakpoint navigator → + → Exception Breakpoint… (All exceptions, On throw)`

## How to diagnose

1. **Console** — Reason line (*** Terminating app due to uncaught exception)
2. **Breakpoint** — Where is it thrown?

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Source: [WhatIsMyError](https://whatismyerror.com/errors/ios/thread-1-signal-sigabrt)