Usually not. The content is typically still in your browser or saved as a draft — the error is about saving to the server, not losing your work. Copy your text out to be safe before you troubleshoot.

It works sometimes but not always — why?

Intermittent 'publishing failed' errors often point to a caching or security layer that only blocks the connection some of the time, or a server that's occasionally overloaded. That on-and-off pattern is itself a clue to the cause.

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Broken After a Change

How to Fix 'Publishing Failed' in WordPress

Updated October 27, 2026

Publishing failed. The response is not a valid JSON response.

What's happening

"Publishing failed" means the WordPress editor couldn't save your post or page to the server, usually because a security plugin, firewall, SSL problem or plugin conflict blocked the connection. Your work usually isn't lost; copy it somewhere safe before you try again.

You hit Publish or Update and WordPress throws back "Publishing failed" or "Updating failed. The response is not a valid JSON response." The change didn't go through, but your text is usually still in the editor.

Why it happens

This one is almost always about the editor not being able to talk to your site's behind-the-scenes system (the "REST API"). Common reasons: a security plugin or firewall blocking it, an SSL certificate issue, a plugin conflict, or a server setting getting in the way. The "not a valid JSON response" wording is just the editor's confusing way of saying "I didn't get the answer I was expecting."

What you can safely try

Copy your text somewhere safe first so nothing's lost while you troubleshoot.
Try again in a different browser or a private window to rule out a browser glitch.
Note whether it started after installing a plugin — especially a security or caching one.
Don't disable security features blindly — that can trade one problem for a bigger one.

When to call us

The fix is finding what's blocking the connection — a plugin, a firewall rule, or an SSL problem — and clearing it without weakening your site's security. That's routine for us. If your editor keeps refusing to save, send it our way and we'll get you publishing again.

Common questions

Did I lose my post?: Usually not. The content is typically still in your browser or saved as a draft — the error is about saving to the server, not losing your work. Copy your text out to be safe before you troubleshoot.
It works sometimes but not always — why?: Intermittent 'publishing failed' errors often point to a caching or security layer that only blocks the connection some of the time, or a server that's occasionally overloaded. That on-and-off pattern is itself a clue to the cause.

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