To resolve the error message "Attempt to read from field 'int.com.elfster.elfdroid...'" in Elfster, follow these steps:

1. Restart the App: Often, simply closing and reopening the Elfster app can refresh the session and resolve temporary glitches.

2. Check for Updates: Ensure that you are using the latest version of the Elfster app. Go to the Google Play Store, search for Elfster, and see if an update is available. If so, update the app.

3. Clear Cache and Data:
- Go to your device's Settings.
- Navigate to Apps or Application Manager.
- Locate Elfster in the list of installed apps.
- Tap on it, then select Storage.
- Choose Clear Cache and then Clear Data. Note that clearing data might reset some preferences in the app, but it can resolve many issues.

4. Reinstall the App:
- If clearing the cache and data doesn't work, consider uninstalling the Elfster app.
- After uninstallation, restart your device.
- Reinstall it from the Google Play Store.

5. Check Permissions:
- Ensure that Elfster has the necessary permissions to function properly.
- Go to Settings > Apps > Elfster > Permissions.
- Make sure all relevant permissions (like storage, contacts, etc.) are enabled.

6. Consult Support Resources: If the problem persists, you may find relevant solutions in the Elfster help center. They provide insights and troubleshooting options for common issues. You can access their help section here - [learn more].

7. Community Assistance: Consider looking for similar issues on dedicated forums or communities such as Stack Overflow. Users often post their experiences and solutions to common problems there. Check this discussion on null object reference issues here - [learn more].

By following these steps, you should be able to resolve the error you're experiencing in the Elfster app. If the issue remains unresolved, consider contacting Elfster's customer support for further assistance.