Sorry – I am not very tech-savvy, so I will try to answer correctly. We post our blog directly to our website, so a custom theme(?). Plugins = Akismet, TinyMCE Advanced, WP to Twitter. All of these settings were installed when I inherited the blog at my job over a year ago, and have not been changed since I have been posting.
Also, I just removed my security scanner and disabled my pop-up blocker and I still get the blank box.
I appreciate your help.
Using Chrome. WP version 3.9.1. I do have pop-up blocker, but I have not changed any of my settings recently. I use the insert/edit link on a weekly basis, and in the past week I now get a blank box.