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Opened 5 years ago

Last modified 3 years ago

#48268 new defect (bug)

Updating failed. Error message: The response is not a valid JSON response.

Reported by: phpdocs's profile phpdocs Owned by:
Milestone: Awaiting Review Priority: normal
Severity: critical Version:
Component: Posts, Post Types Keywords: reporter-feedback
Focuses: Cc:



When i try to update the Page Template from default to full page then i am getting that error "Updating failed. Error message: The response is not a valid JSON response." in WordPress Version 5.3

Attachments (1)

Screen Shot 2019-10-10 at 10.26.21 AM.png (954.0 KB) - added by phpdocs 5 years ago.
Error screen shot

Download all attachments as: .zip

Change History (9)

5 years ago

Error screen shot

#1 @SergeyBiryukov
5 years ago

  • Keywords reporter-feedback added

Hi @phpdocs, welcome to WordPress Trac! Thanks for the report.

Does the issue still happen with all plugins disabled and a default theme (Twenty Nineteen) activated?

#2 @phpdocs
5 years ago

Hi @SergeyBiryukov, yes same issue with Twenty Nineteen and all plugins are disabled.

#3 @phpdocs
5 years ago

@SergeyBiryukov recently i checked same issue with posts.

#4 @diquispe
5 years ago

Same BUG with my site with elementor, disabled themes and plugins with the same error

#5 @ncpr
5 years ago

Seeing same on one of our 5.3 installations using Twenty Nineteen. Happens when editing posts or pages, in any field as far as we can tell, but Quick Edit works for some things just fine.

#6 @nicolebernd
4 years ago

I wanted to provide some info.

I just experienced the same issue after using Elementor and trying to remove it in favor of a more lightweight option. When I disabled Elementor I got the error shown here. When I enabled it again it did not solve the problem. However, I can pinpoint the issue to the moment I deactivated Elementor.

I was trying to save a custom post type made with

I am using WordPress 5.3+ as well as the latest version of Elementor.

Last edited 4 years ago by nicolebernd (previous) (diff)

#7 follow-up: @stidch
4 years ago

I don't know if the issue I face is exactly the same, but at least looks similar.

I cannot save any page, which contain a shortcode, which contain a call to a java-script method

For example:


In my case I try to resize an iframe with the advanced-iframe plugin. The full shortcode looks like this:

advanced_iframe src="" frameborder="0" scrolling="no" onload="resizeIframe(this)"

In an html block above I'v defined the resizeIframe method.

function resizeIframe(iframe) {
  iframe.height = "10px" // required for reducing the size
  iframe.height = iframe.contentWindow.document.body.scrollHeight + "px";

If I remove the part


from the shortcode I can successfully save the page. With I can't.

I've tried already with disabled plugins and default theme.

#8 in reply to: ↑ 7 @stidch
4 years ago

Just found out that my issue is most probably the one which is filed here: #48698

Last edited 3 years ago by SergeyBiryukov (previous) (diff)
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