Verified for macOS Tahoe 26.2
Fix Guide: Mac Contacts App Crashing on macOS Tahoe
Symptom: The Contacts app opens but freezes instantly, or specific contact cards appear blank or cause a crash when clicked.
Why this happens
macOS Tahoe 26.x uses a new data structure for the "Unified Contacts" system. If you have legacy contacts from third-party sync services (like Google or old Exchange servers), the new database can become "locked" while trying to convert old data.
Fix 1: Clear the Address Book Database (Free)
You can force macOS to rebuild your local contacts database from iCloud.
**Quit Contacts**
- Ensure the Contacts app is completely closed.
**Navigate to Application Support**
- In Finder, press `Command + Shift + G`.
- Paste: `~/Library/Application Support/AddressBook`
**Move to Trash**
- Move everything inside this folder to the Trash.
**Restart & Sync**
- Open the Contacts app. It will be empty for a few minutes while it downloads your contacts from iCloud again.
Fix 2: Remove Third-Party Accounts (Free)
If a specific account is causing the hang, you need to isolate it.
**Open System Settings**
- Go to **Internet Accounts**.
**Toggle Off Contacts**
- Turn off "Contacts" for any non-Apple account (Gmail, Outlook).
**Test Stability**
- If the app stops crashing, re-enable them one by one to find the culprit.
Fix 3: The Automated "Identity" Repair
When the local database is physically corrupted.
Manual file deletion sometimes misses hidden system locks. If the Contacts app is still crashing, the local "Identity Services" cache needs a deep reset.
Recommended Tool: CleanMyMac X
- **Maintenance Module:** The "Repair Disk Permissions" and "Speed Up Mail" modules (which shares data with Contacts) can resolve the underlying file system locks.
- **Privacy Scan:** Clears old "Autofill" data that often conflicts with new contact entries in Tahoe.
[Link: Repair Mac Contacts with CleanMyMac X]