Encountering the "Updating Failed. The Response Is Not a Valid JSON Response" error in WordPress can be perplexing, but there's a surprisingly simple solution that might save you from hours of troubleshooting. The secret lies in navigating to your site's Permalinks settings and re-saving them.

Here's a step-by-step guide to this quick fix:

1. Login to Your WordPress Dashboard:
   Access your WordPress admin panel using your credentials.
   
2. Navigate to Permalinks Settings:
   In the dashboard, go to "Settings" and select "Permalinks."
   
3. Make No Changes, Just Save:
   You don't need to modify anything in the Permalinks settings. Simply scroll down and click on the "Save Changes" button at the bottom of the page.
   
4. Refresh and Retry:
   After saving the Permalinks settings, go back to the page or post where you encountered the JSON response error. Try updating or saving your changes again.
   
5. Check for Resolution:
   With the Permalinks re-saved, the error should now be resolved. Refresh the page and see if the changes are successfully saved.

This seemingly unconventional solution works because it refreshes the rewrite rules in WordPress, addressing any inconsistencies that may have led to the JSON response error.

If the problem persists after re-saving Permalinks, you may need to explore other troubleshooting steps mentioned in the initial article, such as deactivating plugins, switching themes, or checking for syntax errors in your code.

Remember, always back up your website before making any changes, especially if you're dealing with troubleshooting or altering settings. While the "Updating Failed. The Response Is Not a Valid JSON Response" error can be frustrating, this quick fix might be just what you need to get your WordPress site back on track.