This is a known issue following major app updates that stems from corrupted permissions in Apple Health.
The following screen will appear on the Apple Watch when the user attempts to start a workout:
"FITIV PULSE Protected Health Data is Inaccessible"
The following procedure resets those permissions:
- Open the HEALTH app on your iPhone
- Click SOURCES>FITIV PULSE and DISABLE everything in this menu
- Restart both the iPhone and Apple Watch
- Return to HEALTH>SOURCES>FITIV PULSE and ENABLE all permissions in this menu (be sure to scroll down to see all permissions)