the response is not a valid JSON response only with Gutenburg editor

Hey, drrichde.

Updating failed. Error message: The response is not a valid JSON response may be caused by issues with shortcodes being used, for instance.

When the short code isn’t written properly, the page can still be saved but that error appears.

What kind of content is being saved in the pages?

Dear lan,

thank you very much for your response. I have many text content and very few photos. I did use shortcodes, but only with the LuckyWP Table of Contents for the contents. And I do not believe the error is caused by shortcodes in my case. Because I have just done a small experiment. I have creatived a new post with only a few words. And I did not seen any error massages by saving or updating. Than I started to add more text in the post. Each paragraph only one word. If the number of paragraphs increased to about 10, the error massage started to appear. If I delete a few paragraphs, the error massage will disappear again.

Hey, drrichde,

I would suggest following these instructions that a plugin author, bfintal, suggested for diagnosing JSON issues – press the update button when doing so – and insert the “response” code you see into a new reply to this thread:

For Chrome:
?
?1. Right anywhere on the page, then select “Inspect” or “Inspect Element” to bring up the browser’s developer tools.
?2. Navigate to the “Network” tab of the developer tools
?3. Click on “XHR” in order to view only ajax calls
?
?You should end up with something that looks like this: https://cloudup.com/ctrVfdDqNh7
?
?Once you’re there, save your page, then check last of the newly added entries in the network tab. Check the “Headers” tab of the new entry and you should see “/wp-json/…” in the “Request URL” to indicate that it’s a rest API call. Check the “Response” tab, the contents of that should ideally start with “{…”. If not, paste here what you’re seeing.

Here is a GIF that I made to demonstrate how to do this: https://i.imgur.com/PWwobhY.gif

Hi Lan,
Thank you very much again for your very detailed description.
I’ve got 3 entries with “/wp-json/…” The first one just had an empty “Response”. The other two had both the same “Response”
{“message”:”CSS updated.”}