Bug report – editor in “not saved” state

Update: I tested other plugins, e.g. Polylang, and it causes the same issue – it might be some kind of incompatibility or bug in new WordPress 5.9

My plugin does not have anything to do with the block editor at all – it will only be active when the frontend output is rendered.

So I assume this is a local problem on your website.

Hello,
as I wrote in an update, it is an issue with many plugins, and in lot of my sites – if I disable all plugins issue does not exist, but if I enable single one, e.g. Lightbox with photoswipe or Polylang – issue appears.

I would say it is an issue with WordPress in general.

I just checked this on my demo website https://wordpress-demo.arnowelzel.de.

No problem – editing works fine with WP 5.9 even with all plugins enabled. So it must be a problem with your website. Maybe you use some “security” stuff like Wordfence etc.?

Hello Arno, I just traced the root of the problem.
First, are you using Block editor (Gutenberg)? If not, the error might not appear – classic editor should be disbled, and only block editor should be used.
I also reported the problem here: https://github.com/WordPress/gutenberg/issues/38411
Apparently, your plugin creates a metabox in classic editor, which are not used anymore in block editor.
If you want, I can help with writing the metabox for block editor. Let me know.

Cheers!

Yes I use the block editor in Gutenberg and yes, it works.

Also the metabox just works – it will not be displayed in the “new” way but it still works even if it is added the “old” way.

See the screenshot: https://nextcloud.0x0c.de/s/FBPyFbGQY65WM5L/preview

I also don’t see the point why code for a classic metabox should cause WordPress not to save a post. The code which saves the metabox selection does not touch the post at all – it will update a setting in my plugin to record if the lightbox should be disabled for this post ID or not.

You can also verify this by disabling “Show this setting as checkbox in page/post editor” in the general settings of Lightbox with Photoswipe (also see https://github.com/arnowelzel/lightbox-photoswipe/blob/main/lightbox-photoswipe.php#L144-L148).

Hello, I just did verify this. And the issue is not that metabox does not appear. The issue is that post is after updating again in “unsaved” state (update button is NOT disabled). Are you sure you use WordPress 5.9 and Classic editor removed? It would be weird that it happens only to me, especially with all other plugins disabled and on many sites.

I will check this with a completely fresh installation. So far I could not reproduce this within Gutenberg with a website which uses Gutenberg but also has the classic editor available.