Having issues enabling "Use your Apple Watch to Unlock apps and your Mac" and keep getting, "Your Mac was unable to communicate with your Apple Watch," or "Make sure your Apple Watch is unlocked and on wrist, and your iPhone is unlocked"?

Keep getting "Make sure your Apple Watch is unlocked and on wrist, and your iPhone is unlocked." and "Your Mac was unable to communicate with your Apple Watch." errors? The below solution worked for me after attempting the many solutions I've seen over the past few days...

Source: https://discussions.apple.com/thread/251826134?answerId=253529745022#253529745022

I've finally fixed it! I found a bunch of errors related to "AutoUnlock" in the Console that was hinting to me that there was some invalid state on my Mac with keys and plists not being reset properly. 

Steps (follow at your own discretion)

1. Open "Keychain Access"

2. In "View", enable "Show Invisible Items"

3. Search for "Auto Unlock"

4. You should see a whole bunch of application passwords for "Auto Unlock: XXXX's ..."

5. Select all records and delete (this will reset/disable auto unlock on other Macs if you use multiple Macs)

6. Whilst still in "Keychain Access", search for "AutoUnlock" (no space)

7. There should be 4 entries for "tlk" "tlk-nonsync" "classA" "classC"

8. Select 4 records and delete (don't worry if they re-appear, the system repairs this automatically)

9. Open "Finder" and navigate to "~/Library/Sharing/AutoUnlock"

10. There should be two files "ltk.plist" and "pairing-records.plist"

11. Delete both files

12. Open "System Preferences" and try enabling auto unlock. You may need to enable it twice, the first attempt will fail

Yes, I deleted all the entries and files mentioned here and the logins and certificates automatically re-entered themselves. No restart, just check Use your Apple Watch to Unlock apps and your Mac

• macOS Catalina
• Apple Watch SE

Hope this helps!