If the MegaNovel app opens and then closes immediately, follow these steps to troubleshoot and resolve the issue:

1. Restart Your Device:
- Completely power off your iPhone.
- Wait for about 10 seconds.
- Turn it back on and try launching the MegaNovel app again. This can clear temporary glitches that might be causing the app to crash.

2. Update the App:
- Open the App Store.
- Go to the 'Updates' tab.
- If MegaNovel appears in the list, tap 'Update'. An outdated app version could be incompatible with your current iOS.

3. Check for iOS Updates:
- Go to Settings > General > Software Update.
- If there’s an update available for iOS, install it. This ensures your phone has the latest features and bug fixes that could solve app issues.

4. Reinstall the MegaNovel App:
- Press and hold the MegaNovel app icon until it jiggles.
- Tap the 'X' to delete the app.
- Open the App Store, search for MegaNovel, and reinstall it. This can fix corrupted files causing the app to crash.

5. Clear App Cache (if applicable):
- Unfortunately, iOS doesn’t offer a clear cache option directly. However, reinstalling the app as mentioned above usually helps clear any persistent cache problems.

6. Check Background App Refresh:
- Go to Settings > General > Background App Refresh.
- Ensure that it is enabled for MegaNovel, as disabling it can sometimes restrict app functionalities.

7. Reset All Settings:
- If the problem persists, consider resetting all settings. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset All Settings.
- This will reset your system settings without deleting your personal data.

8. Contact Support:
- If none of the above steps work, consider contacting MegaNovel support through their official channel. They may have more specific troubleshooting steps or updates regarding known issues.

If your issue remains unresolved, you can check online resources for trends or reported issues, such as community discussions on platforms like Reddit, where users report similar problems and solutions - learn more - learn more.