I've noticed lately that my Highlights and Full Description edit blocks are blank untill I increase or decrease the page size using Ctrl- +/- keys. This only started a month or so ago, and I'm not sure exactly what might be done.
Currently, I have to adjust screen magnification to see the contents, very strange behavior!
I have not tried changing the editor, however. Will test that and report back shortly (just thought of it as I was typing this!)