For this one k2-item only, the Publishing & Metadata Tab and Display Settings Tab is blank.

https://www.dropbox.com/s/b3wuw4tmab06krv/image001.png?dl=0

What is the problem and how do I resolve it

If you check the source, is the markup there?
Can you also enable error reporting so we can see if there is a PHP error?

The markup is there but is set to display: hide.
https://www.dropbox.com/s/d612br6v4jui70w/Screen%20Shot%202017-07-31%20at%2012.32.03%20PM.jpg?dl=0

I see nothing even if I set Error reporting to Development.

It's odd because this is only happening with this one particular K2-item. All other k2-item's Publishing & Metadata Tab and Display Settings Tab work perfectly.

Are there any JS errors?
Any K2 plugins that you might be using?

I have finally been able to update to 2.8.0 but this did not resolve this issue.

But I have figured out what is happening, just not why.

If there is a URL in the "Browse server or use remote media" then the "Publishing & Metadata" tab will be blank.
https://www.dropbox.com/s/lohtq90ysu2bosm/Screen%20Shot%202017-09-28%20at%209.58.24%20PM.jpg?dl=0
https://www.dropbox.com/s/l6qa5yrof74e1xb/Screen%20Shot%202017-09-28%20at%209.58.31%20PM.jpg?dl=0

If I use the " Check this box to delete the current item media or use the form above to replace it" , click save, then the Publishing tab will display correctly.

Kirkor,

I have confirmed again that having a url in the Media tab prevents the Publishing tab from displaying.

Do you have any idea what is going on?

Still, I can't verify the issue.
Did you update AllVideos to the latest stable version?