Your Mac was unable to communicate with your Apple Watch.
When I installed WatchOS 7 on my Series 4, I had terrible problems with the battery life. Usually when I put my watch on the charger at night, I would have about 50% battery left. After the update, my watch would last maybe 8-10 hours and then I'd start getting the 10% battery warnings. One of the solutions I found online was to unpair my watch from my iPhone and then pair it again. Doing this appears to have fixed the battery drain problem, but now I can not turn on the option to unlock my MacBook Pro with my watch.
To enable unlock with my watch I go to System Preferences -> Security & Privacy and tick the "Use your Apple Watch to unlock apps and your Mac." Sometimes I get prompted for my password to unlock my disk and sometimes I don't. In either case, "Turning on..." with a spinning icon is displayed for a few seconds, and then I get an error message from the subject of this post. It also says to "Make sure your Apple Watch is unlocked and on wrist, and your iPhone is unlocked."
This was working before I unpaired and re-paired my watch. I have tried all of the suggestions that searching for this error message brings up, including restarting everything, making sure everything is on the same WiFi network, disabling/enabling handoff, restarting bluetooth, disabling/enabling auto-unlock of watch from phone, logging my MacBook out of iCloud and back in again, etc. Nothing seems to help me get this option enabled again.
I would really like to get this option turned back on again. Any other suggestions?
MacBook Pro 15″, macOS 10.15