NSInvalidArgumentException

iOS

TL;DR

NSInvalidArgumentException indicates a runtime failure on iOS that interrupts the current user flow.

Symptoms

  • NSInvalidArgumentException appears in crash logs
  • The app exits or the UI flow stops

Common Causes

  1. Unexpected state reaches an unsafe path
  2. Input contracts are not enforced at boundaries

How to Verify

Quick Fixes

  • Add guard checks and a safe fallback path
  • Disable or rollback the risky code path behind a flag

Proper Fixes

  • Enforce contracts with types, runtime checks, and tests
  • Refactor ownership and lifecycle boundaries to remove the failure mode

Example Stack Trace

NSInvalidArgumentException in ProfileViewController.swift:42

Related Errors