If your FitCloudPro Diar library is empty, follow these steps to troubleshoot and potentially resolve the issue:

1. Restart Devices
Turn off both your smartwatch and your phone. After a brief moment, turn them back on. This simple step can often resolve syncing issues that might influence the visibility of the Diar library.

2. Check for App and Phone Updates
Ensure that both the FitCloudPro app and your phone's operating system are up to date. Sometimes, the app may not function properly if updates are not installed.

3. Sync Your Smartwatch
Open the FitCloudPro app and manually sync your smartwatch to see if that populates your Diar library. Make sure that your smartwatch is connected via Bluetooth.

4. Clear App Cache and Data
Go to your phone's Settings > Apps > FitCloudPro > Storage and select Clear Cache and Clear Data. Then, reopen the app and attempt to sync your watch again. This can often resolve persistent data issues— learn more.

5. Reset Network Connection
If the issue persists, reset your network connection. You can do this by turning off your phone's Wi-Fi and Bluetooth, waiting for a few moments, and turning them back on. Then try syncing the app once more.

6. Reinstall the FitCloudPro App
If clearing cache and data doesn't solve the problem, consider uninstalling and then reinstalling the FitCloudPro app. This can provide a fresh installation which might resolve underlying issues— learn more.

7. Contact Customer Support
If none of the above steps work, it may be best to reach out to customer support for further assistance. They may have access to advanced troubleshooting steps or be able to provide information on any ongoing issues with the app or device compatibility.

Following these steps systematically should help in diagnosing and potentially resolving the issue with the empty Diar library in your FitCloudPro app. If you continue to experience difficulties, seeking support from the FitCloudPro community or customer service might lead to a more specific solution.