Fix Guide: "Unknown Caller" Bug in macOS Tahoe Phone App
Symptom: When receiving a call on your Mac (via iPhone continuity), the caller ID shows as "Unknown Caller," even if they are in your Contacts. Or, the Phone app randomly quits during a call.
Why this happens
This is a synchronization bug between the macOS Tahoe "identity daemon" and iCloud Contacts. The system fails to pull the VCF data fast enough to display the name during an incoming call, defaulting to "Unknown."
Fix 1: Force a Contacts Sync (Free)
Force the identity daemon to "re-read" your iCloud address book.
**Sign Out of iCloud**
Go to **System Settings > [Your Name] > Sign Out**.
*Note: Choose "Keep a copy" of your data to be safe.*
**Sign Back In**
Restart your Mac.
Sign back into your Apple ID.
**Toggle Contacts**
Ensure "Contacts" is toggled ON in the iCloud settings list.
Fix 2: Reset the "identityservicesd" Process (Free)
This process handles the "Who is this?" logic for FaceTime and Phone calls.
**Open Terminal**
Go to Applications > Utilities > Terminal.
**Kill the Daemon**
Type: `killall identityservicesd`
The system will automatically restart the process.
**Wait for Re-index**
Give the system 5 minutes to re-map your contacts to their phone numbers.
Fix 3: The Pro "Identity" Cleanup
When corrupted contact "ghosts" are blocking the sync.
If you have duplicate contacts or old, broken VCF files, the Tahoe identity daemon will "timeout" while searching, resulting in "Unknown Caller."
Recommended Tool: CleanMyMac X
- **Contacts Cleanup:** CleanMyMac X has a module to find and merge duplicate contacts and repair the local database files that the Phone app relies on.
- **Privacy Module:** Clear out the "Call History" and "Chat Caches" to ensure the system is starting with a clean slate.
[Link: Fix Sync & Contact Bugs with CleanMyMac X]