I just applied a new theme to three different C5 sites for the same business and then upgraded each to the C5 version 5.6.3. After doing so, when going in to edit a Content block on one of the sites, I discovered that the editing buttons in the Tiny MCE editor had disappeared (see screen shot). At first I thought it must be a CSS conflict with the new theme so I switched the theme to Greek Yogurt on the page and found that the editing buttons were still gone. I then checked one of the other sites and found it had the same issue. I figured it must have been a bug in 5.6.3 and 5.6.3.1 had just come out so I upgrade one of the sites but the problem still persists. Firebug doesn't show any errors. Anyone have any guesses? I'm a little stumped.