How do I fix missing input fields in panels The site I am working on is Drupal7 site, built of panels and pages, panelizer.  Typical steps to edit, admin logs in, click on the &quot;customize this page&quot; button, various panels open up, click on the gear of the panel you want to edit, edit screen opens, make your updates, click finish then slick save, and all is right with the world.
Yesterday one of the editors, following the steps above, attempted to edit, but the panels input box, for some reason, the actual area where you would add the content is collapsed/gone.

It should look something like similar to this:

Anyone have any idea on what is causing this or where should I even start checking to see why all the fields are not displaying?
Any and all suggestions would be appreciated.
Thanks in advance.
Just a reference for those who come along after this. 

Try to find out if anyone else has touched your code specifically .js or .CSS and CSS was the issue here.  ONe of the content editors added some css into a block: fieldset{display:none;} well that closed the fieldsets in that popup window and I am sure in other places on the site that we had not run into yet.