To resolve the "Last Line Loading" runtime error in Natural Reader, follow these detailed steps:

1. Restart the Application: Close Natural Reader completely and reopen it. Occasionally, this can resolve temporary glitches causing runtime errors.

2. Check for Updates: Ensure that you have the latest version of Natural Reader. You can do this by navigating to the settings or help menu within the application and selecting the option to check for updates. If an update is available, download and install it.

3. Reset Application Settings: In some cases, corrupted application settings can lead to runtime errors. Look for an option in the settings menu to reset the application to its default settings. This may help eliminate any conflicts causing the error.

4. Clear Cache and Temporary Files:
- If you're using Natural Reader online, try clearing your browser cache and cookies.
- If on a desktop version, look for any options to clear cache within the app settings.

5. Reinstall the Application: If the error persists, consider uninstalling Natural Reader and then reinstalling it. Make sure to back up any custom settings or files before uninstalling.

6. Check Internet Connection: If you're using Natural Reader Online, ensure your internet connection is stable. Connectivity issues can sometimes lead to runtime errors. Try to reconnect or reset your router if necessary.

7. Contact Support: If none of the above steps work, consider reaching out to Natural Reader's customer support for specialized assistance. You can find FAQs and support options on their official websites:
- NaturalReader Online FAQs - [learn more]
- NaturalReader Software FAQs - [learn more]

8. Monitor Related Forums: Keep an eye on technical forums or communities, such as Google Groups, where users might discuss similar issues and solutions found.

By following these steps, you should be able to address the "Last Line Loading" runtime error effectively.