Seeing I got caught off-guard with a little disaster yesterday (all good training I'm sure), I thought I would mention something to be aware of. When I installed my Joomla a few days ago and played around with it, I did the upgrade from 3.62 to 3.63 and quit for the day. The next day, (yesterday) I went to add some modules and had some weird problems where the editor would open briefly, then the page went to a white background with a small drop down box in the upper left corner. I was clueless. I tried deleting the 2 Joomla cache options but it did not fix anything. So I did my first Akeeba restore and botched it by not entering the correct passwords due to my pen covering up the last character of them. :S So I restarted from scratch and installed Joomla, updated Joomla, and then my templates and modules and plugins. Same problem. I googled it and found that there was in fact a problem with Joomla 3.63 where the fix was to delete your BROWSER CACHE. That fixed it. Just a heads up. CTRL-F5 with Firefox deletes the cache but I recommend you do it while on the modules page as that was my experience anyhow.
schemer

p.s. I just signed on to my wifes Joomla site and updated Joomla to 3.63 and went to the modules page and clicked on a module and it happened there too. The fix worked as I explained by hitting the CTRL-F5 after closing the window and going back to the modules page. Hope that helps.