Just upgraded this morning to WP5.3 and MB stuff to their latest versions and noticed the following:
I do use IMAGE_ADVANCED to provide a metabox for a custom gallery inside my posts.
Everything works as expected, however — when you move the mouse over the thumbnail — the EDIT LINK (the little pencil icon) opens the image edit screen on a _BLANK window/tab, instead of opening on the traditional iframe as before.
The same happens everywhere, whenever I use IMAGE uploads metaboxes. For example, I have a custom metabox to upload the website logo on the SETTINGS PANEL extension, and, clicking on the PENCIL icon at the image there, acts the same. Brings a new window/tab to edit the image instead of the traditional super quick iframe window.
Is this WP5.3 related? Or is this some change made by purpose on latest metabox version?
I see no errors on the console and — comparing the HREF info of the pencil icon with WP5.2.4 it is exactly the same.
I am experiencing the exact same problem. I noticed this issue in one of my sites after I updated WordPress to 5.3.
To reproduce this I did a clean install of WordPress 5.3, theme twentytwenty and ONLY the metabox.io plugin. I created an image_advanced field and tried to edit an image. I recorded the issue and I did get an error in my console.
I don't see any options to include the recording here, so I will send this in a seperate support ticket.