Error saving created pattern

Confirm it’s really a theme issue. Deactivate all plugins and try again. If you are able to save now, the problem was a plugin. Reactivate your plugins one at a time, testing after each to find the responsible plugin. Take up the issue through that plugin’s dedicated support channel.

If the problem persists with no plugins active, there is a dedicated support forum for the theme. The volunteers and support staff there are in the best position to help you.

Thanks for the answer.
There are no active plugins on the site. Installed pure wordpress-6.3.
I’m trying to create the theme I need.

I’m unable to replicate such an issue on my site using Twenty Twenty-two and no plugins.

I’m trying to create the theme I need.

Have you altered or added to the theme’s code? Or by “theme” do you mean by creating patterns and templates using the editor? The latter is fine. You should not alter the theme itself though. To customize a theme you should create a child theme to contain your customizations.

If your theme remains unaltered and you save attempts fail, there’s likely a problem with your server configuration. Check the site health screen to see what issues might have been flagged. Anything related to the API or loopbacks would certainly affect your ability to save.

After you get a saving failed message, check both your browser’s console log and server’s PHP error log for any related errors that indicates what the root cause of the problem might be.

I am working on a local Open Server. Installed a clean version of WordPress-6.3.
I want to create my own theme. I create it from Twenty Twenty-Two.
To do this, I created a child theme and started the changes from the title. Went into patterns->template parts->header and created a new header type pattern. Named it “Header(Mine)”. Added a group, and in it Image and Header. I save.
I get “Save failed”. At the same time, the “Header(Mine)” pattern was created, but empty.
In the previous version of WordPress-6.2, everything was preserved.
The situation is similar in other topics.

Are you able to save patterns with just the Twenty Twenty-two theme active, without your child theme?

It won’t save without a child theme either.

We apparently each have the exact same WP installations, 6.3, 2022 theme, no plugins. I cannot replicate the issue, so I have to think there’s something off with your server configuration. That’s where we differ. I’m using Apache/PHP natively installed in Linux.

As I said before:
“Check the site health screen to see what issues might have been flagged. Anything related to the API or loopbacks would certainly affect your ability to save.

After you get a saving failed message, check both your browser’s console log and server’s PHP error log for any related errors that indicates what the root cause of the problem might be.”

Thanks for the help. It turned out to be really in my local server.
I reinstalled Open Server and the save error disappeared. Now everything is saved.
Sincerely, Vladimir.