I have created an alert button link and am using JCE MediaBox to open an article on my site in a popup window.
Is there a way to have the focus move to the pop up window rather than the page beneath the pop up?

Sure. Here is a link: https://bit.ly/2Ymncfy

You’ll see two red alert button links under the menu.

When the pop up opens, you can't navigate through it using the tab key like you can throughout the rest of the site's content.
So for example, if I hit tab trying to navigate to a link within the text, nothing happens. Also if the focus is on the close button, then I'd have to assume a screen reader wouldn't read any of the text in the pop up window. For this website, that's an important consideration.

I'll need to present another solution for my client if the focus cannot be set to move to the content of the window.

Thanks

Thanks for the new version to try. I can report that focus is now within the content when the window opens and I can navigate using the tab key.
Only thing I was still concerned about was that the "Close" link focus color didn't provide enough of a contrast to make it obvious that focus was on the close button.
Got around that by adding a rule to my custom style sheet and it now turns red on focus.

I'm happy with this - thanks very much :)

In reference to the new beta version of MediaBox you provided me with back in December (JCE MediaBox 2.0.14 Beta 4)
I was working on the site where I installed this beta version today, and noticed that if you create a new link, the class jcepopup is by default assigned as follows:

<p><a class="jcepopup" href="https://www.joomlacontenteditor.net/#" data-mediabox="1">link</a></p>

The only way I can get rid of the class is to go into the html and strip it out. I tried removing it through the editor, but once I hit update it saves with the jcepopup class.
Any idea why that might be happening?

Perfect thanks so much for the quick reply