Hello brutus inquisitor,
Thanks for participating in the Apple Support Communities.
When this occurs, check to see if your Apple Watch is connected with your iPhone. This will help to determine if this is due to the connection between your devices or not. For assistance with determining this, check out the following resource: If your Apple Watch isn't connected or paired with your iPhone - Apple Support
If you are connected with your iPhone when this occurs, let's try a restart of your Apple Watch to see if the message appears at this time. For assistance with a restart of your Apple Watch, take a look at this resource: Restart your Apple Watch - Apple Support
Should the message appear again, let's unpair your Apple Watch to establish a new connection with your iPhone. Once you erase and unpair your Apple Watch, a backup is created at that time for you to restore from. For assistance with erasing and unpairing, check out these steps: Unpair and erase your Apple Watch - Apple Support
When you're ready to pair your Apple Watch again, use these steps: How to pair your Apple Watch with a new iPhone - Apple Support
We hope that's able to help.
Have a great day!