“Updating failed. The response is not a valid JSON response.” Error

Are you using the block (Gutenberg) editor?

With the introduction of the block editor, WordPress relies more heavily on REST-calls between the parts. These calls use JSON-formatted data to communicate. The calls and thus their data are queued until the call scheduler handles them. If the data is properly formatted and there are not too many calls to overflow the queue everything works nicely.

However if data is malformed, you get a JSON error. And if the queue gets overflown, you get a gateway error.

What happens if you edit the last post/page with the Classic editor? Do you still get the error?

Yes I am using the Gutenberg editor.

I don’t get the error with the Classic editor, but I’d like to keep using Gutenburg or blocks.

I think you have nailed this well down: there is a JSON error in the plugin.

Thanks, is there any way to contact the developer?

Thanks for the report. At this stage, I haven’t investigated further but I’m not sure why it would start to break updates now particularly when the plugin doesn’t do anything with JSON?

What were you trying to update? Was it WordPress or this plugin? From what version to what?

Are you using any extra Gutenburg plugins?

@conjur3r I updated wordpress and I currently have WordPress 5.9 version.

I don’t use any extra Gutenberg plugins and have only about 10 plugins in total _ including yours. I did a troubleshoot, and it’s your plugin causing the error ;/

@conjur3r Any update?

Hi Iamaileen

I’m afraid I haven’t been able to replicate your problem and I’ve tried on many different grade installations (dev, production) using common configurations available (Nginx, Apache, mod_php, php-fpm) and on single and multi-network installs.

I’ve tried upgrading WordPress via the dashboard as what you would have done. I’ve tried the following upgrades:

5.7.2 -> 5.9.2
5.8 -> 5.9.2
5.9 -> 5.9.2
5.9.1 -> 5.9.2

As you can see, I’ve upgraded between major and minor versions but I haven’t encountered the JSON problem. Before each upgrade, I ensure I have table-of-contents-plus enabled and working and I’ve had pages that use Gutenberg as well.

I googled “Updating failed. The response is not a valid JSON response” and it appears to be common with a number of suggested options. Have you tried the permalink one? Most of my sites use “Month and name”. However, I also tested this by changing it back to “Plain” and running through an upgrade but it completed successfully.

Unfortunately, as I’m not able to replicate the problem, at this stage, I can’t confirm it is a problem with the plugin. If others are having the same problem, I’d ask that they add to this conversation and help narrow down the cause. Until then, I’m not able to help any further.

Hello,

I just would like to say that I am also having this issue.

In french, the JSON invalid response error say : “La mise à jour a échoué. La réponse n’est pas une réponse JSON valide”

Disabling TOC+ solve the issue.

I am using Genesis theme in this website + Divi Builder O.O.

## System Status ##
:: 2022-07-12 @ 17:32:44 UTC

  Writable wp-content Directory
  1

  PHP: Version
  8.1

  WordPress Version
  6.0.1

  PHP: memory_limit
  1024M

  PHP: post_max_size
  128M

  PHP: max_execution_time
  180

  PHP: upload_max_filesize
  64M

  PHP: max_input_time
  300

  PHP: max_input_vars
  8000

  PHP: display_errors
  0

 Plugins installed : 

Autoptimize
Better Search Replace
Change wp-admin login
Divi Builder
Duplicator
Email Encoder - Protect Email Addresses
Sucuri Security - Auditing, Malware Scanner and Hardening
Table of Contents Plus
TinyPNG - JPEG, PNG & WebP image compression
UpdraftPlus - Backup/Restore
WP Custom Post Type Feed
WP Super Cache
XML Sitemap & Google News

Hope this help.

Keep going thanks!

On my side it is the “WP Ultimate Search” plugin that was the problem.
https://fr.www.ads-software.com/plugins/wp-ultimate-search/