If the NSDL app is not starting or functioning properly, you can follow these step-by-step solutions to troubleshoot the issue:

1. Check Your Internet Connection: Ensure your device is connected to a stable internet connection, as a weak or interrupted connection can prevent the app from accessing required services.

2. Restart Your Device: Sometimes, a simple restart can resolve any temporary glitches that may be affecting app performance.

3. Update the NSDL App: Make sure you are using the latest version of the NSDL app. Check the Google Play Store (for Android) or the App Store (for iOS) for any available updates and install them.

4. Clear App Cache and Data (For Android Users):
- Go to Settings > Apps or Application Manager.
- Find and tap on the NSDL app.
- Select Storage and then click on Clear Cache and Clear Data.
- Restart the app to see if it resolves the issue.

5. Reinstall the App: Uninstall the app from your device and then reinstall it from the appropriate app store. This can help resolve any issues associated with corrupted files.

6. Check for Device Compatibility: Ensure that your device meets the app's requirements, as performance issues can arise on devices that do not meet these specifications.

7. Look for Interfering Apps: Sometimes third-party apps can interfere with the operation of other apps. Consider booting your device in safe mode to check if the NSDL app functions properly there. If it does, another app may be causing the issue.

8. Check for System Updates: Ensure that your device's operating system is up to date. Go to Settings > System > Updates, and install any available updates.

9. Consult Online Resources: If problems persist, refer to video tutorials and resources that address common issues with the NSDL Jiffy app. For instance, a helpful video on fixing the app issues is available here: YouTube Tutorial - [learn more] and YouTube Fix - [learn more].

10. Contact Customer Support: If none of the above steps work, consider reaching out to NSDL e-Governance customer support for further assistance.

By following these steps, you should be able to identify and rectify the issue with the NSDL app not starting.