I had the same thing. I went and updated all my plug-ins and it corrected the error. I hope this helps.
I was able to get it to work by copying the CSS from the toolbar.css (find the link to toolbar.css in the setting page for the plug in) and pasting it into my Style.css for my theme. I had to do a little tweaking to get it to look nice. Not sure if that will work for everyone however, wanted to share.
