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DevLens

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Paste an error, crash log, code snippet, API response, or screenshot. DevLens finds the problem and shows you what to fix — like a second pair of eyes on the desk.

AppDelegate.swift

Thread 1 crashed

38func loadSession() {39let user = currentUser!40profile.label = user.name41}Fatal error: Unexpectedly found nil while unwrapping an Optional

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02

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03

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crash.log

input

Thread 1: Fatal error:
Unexpectedly found nil while
implicitly unwrapping an Optional value

Diagnosis

Force-unwrapped optional is nil

SwifthighConfidence: 91%

What's wrong?

A value declared with `!` is nil at runtime.

Why it happened

The optional is being force-unwrapped before it contains a value.

Fix

Safely unwrap the optional before using it.

Beforeswift
let user = users.first!
Afterswift
guard let user = users.first else {
    return
}

Evidence

The crash message explicitly references an implicitly unwrapped optional, which strongly indicates a nil value was accessed.

Check this next

  • Verify where `users` is populated.
  • Confirm the array isn't empty.
  • Inspect the value immediately before the crash.

Stack

Built for the stack you already use

DevLens is strongest on the technologies below. It can still inspect other errors — we don't claim perfect support for every language or framework.

  • Swift
  • SwiftUI
  • UIKit
  • Objective-C
  • React Native
  • TypeScript
  • JavaScript
  • Node.js
  • Firebase
  • REST APIs