Hi there! I’m Grace. I understand you were able to use the biking exercise on your Da Fit app yesterday, but today the exercise app won’t start at all. Let’s see if we can get this working for you.

To get started, could you tell me if the Da Fit app itself opens but the biking exercise just won’t start, or does the entire Da Fit app fail to open? Also, are you seeing any error messages or just nothing happens when you try to start the exercise?

Meanwhile, here are a few simple steps you can try to troubleshoot the app not starting:

1. Restart the app and your device: Close the Da Fit app completely (make sure it is not running in the background), then restart your Windows device and try opening the app again.

2. Update the Da Fit app: Check the app store or official source from where you installed the app to make sure you have the latest version. An outdated app can cause functionality issues.

3. Check internet connection: Confirm your Windows device is connected to a stable internet network, as some features might require data sync.

4. Clear app cache (if applicable on your platform): Sometimes the app cache can cause issues. You can try clearing the cache or reinstalling the app after uninstalling it.

5. Bluetooth connection: If your biking exercise requires connection to a Da Fit watch or device, ensure Bluetooth is turned on and properly connected.

Could you try these and let me know if the problem persists? If these don't help, I can walk you through some deeper troubleshooting steps. Also, let me know if your Da Fit app is connected to any smart device or watch.

Looking forward to your reply!