I just upgraded a couple of stores, and in the Admin section the drop down boxes are gone the list just opens below the input field, what happened? This is really annoying when picking countries from the forever long list. (not a theme issue, it is this way in Twenty-Fourteen). I tested in Firefox and the boxes are working, but in Safari, it is not and I hate using Firefox!!
Plus it seems a lot of issues are being posted here. I have clients that will freak if the store breaks, I am going back to the previous store version and just will have it on a test site until I can learn about all of the intense changes and do tests so that nothing breaks a functioning store.