Appearance –> Editor glitch. Doesn't give access.

Hi,
I am experiencing a glitch which won’t allow me to access different editor files. When the drop down populates, it extends to a left corner of the screen which is un-clickable and not findable. To my knowledge, I am updated on the theme, wordpress, etc. While I was building the site on a local host, this problem was not present. It appeared when I began hosting the site live.

Any suggestions?

http://www.legaldemandletters.com/wp-content/uploads/2015/03/Dwm-2015-03-31-11-41-41-30.jpg