Workaround: Publishing failed. The response is not a valid JSON response in WordPress

All of a sudden my website is displaying this horrible red message whenever I try to publish an article: Publishing failed. The response is not a valid JSON response in WordPress. I am writing using the Gutenberg editor.

Publishing failed. The response is not a valid JSON response in WordPress Gutenberg editor.

What I tried and didn’t help

  1. Update WordPress to latest 5.7.1
  2. Update all Plug-ins to their latest versions
  3. Change permalink structure (although on a live site this should never be done so afterwards I had confirmed this did not solve my issue I changed the setting back to original to not affect link structure)

How to use the workaround to still publish articles while this issue persists?

  1. Save your article as draft
  2. Go to the posts list and hover with your cursor over the article title area
  3. Click on the “Quick Edit” button

4. Use the Status dropdown to select “Published“.

5. Click “Update” and the post should publish.

Hope this helps.

This is how I managed to post my posts while the error of a not valid JSON response was present.

Error "Publishing failed. The response is not a valid JSON response" in WordPress
Error “Publishing failed. The response is not a valid JSON response” in WordPress

The fix seems to be a strange one so this workaround gives everyone some method to still keep on publishing the articles.

Post Author: Tom Pai