macOS app crashes on launch — fix in under 20 minutes

The 30-second fix: reset app permissions

You click the app. The icon bounces in the dock. Then… poof. Nothing. Or it crashes with a generic "unexpectedly quit" message. I know how frustrating that is — especially when you're in the middle of something.

Before you dive into Terminal or delete system files, try this. macOS uses a permission database (the TCC database) that can get corrupted after an update or when you install a new app. Resetting permissions for a specific app often fixes this.

1. Open System Settings (or System Preferences on older macOS).
2. Go to Privacy & Security.
3. Scroll through each category — Camera, Microphone, Files and Folders, etc. — and look for your app. If you see it listed, click the toggle to turn it off, then click turn it back on.
4. Launch the app again.

Why this works: The TCC database maps app permissions. If the entry is stale (common after macOS Sonoma 14.4 or Ventura 13.6 updates), the app sees a permission mismatch and crashes. Resetting the flag forces macOS to re-request access.

If the app doesn't appear in any privacy list, skip this step — it's not a permission issue.

The 5-minute fix: nuke the app cache

Still crashing? The next most common culprit is a corrupted cache file. Apps store preferences, thumbnails, and temp data in specific folders. When that data goes bad — usually after a crash or an update that didn't fully complete — the app chokes on startup.

Here's the real fix — don't waste time deleting individual files. Clear the whole app cache:

1. Quit the app completely (Force Quit if needed: Cmd + Option + Esc).
2. Open Finder and press Cmd + Shift + G to open the "Go to Folder" dialog.
3. Type ~/Library/Caches and hit Enter.
4. Find the folder that matches your app's name (e.g., com.apple.Safari or com.microsoft.Word). Drag it to the Trash.
5. Empty the Trash.
6. Launch the app again.

If you're not sure which folder belongs to the app, check the app's name in ~/Library/Containers (for sandboxed apps) or look for a folder with the app's bundle identifier. For example, Slack uses com.tinyspeck.slackmac.

A personal tip: I've seen this fail only when the app also has a separate preference file (~/Library/Preferences/com.yourapp.plist). If cache clearing doesn't work, delete that plist too (same method — but back it up first by copying it to your desktop).

The 15-minute fix: rebuild the LaunchServices database

If the first two steps didn't help, the problem is probably deeper. The LaunchServices database — the system registry that tells macOS which app opens which file type — can get corrupted. This is especially common after upgrading from Ventura to Sonoma, or after installing beta versions of macOS Sequoia.

A corrupted LaunchServices database can cause any app to crash on launch, even ones that worked fine yesterday.

Step 1: Quit every app except Finder

Force quit everything: Cmd + Option + Esc and kill all non-essential processes. Leave only Finder open.

Step 2: Run the Terminal commands

Open Terminal (from Applications > Utilities). Run these commands in order:

/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

sudo killall -HUP mds

This kills the LaunchServices daemon and clears the cache. The -r flag rebuilds it, and -domain local -domain system -domain user covers all scopes. The sudo killall line restarts the metadata indexer (Spotlight), which sometimes holds onto corrupt data.

You'll be prompted for your admin password. Type it (nothing appears on screen — that's normal) and hit Enter.

Step 3: Restart your Mac

Don't skip this. A full restart forces macOS to rebuild the LaunchServices database from scratch. After reboot, try launching the app.

When to call it quits

If the app still crashes after all three steps, it's likely a broken app binary — not a macOS issue. Try:

• Reinstalling the app (drag to Trash, then download a fresh copy).
• If it's an Intel app on Apple Silicon (M1/M2/M3), enable Rosetta 2: right-click the app > Get Info > check "Open using Rosetta".
• Check the developer's support site for known macOS compatibility issues (e.g., older Adobe apps on Sonoma).

One last thing: If you're running macOS Sequoia beta, app crashes are common. Don't waste time on deep fixes — report the crash to Apple and wait for the next beta update. I've learned that the hard way.