The weird thing about finding a bug is that sometimes you don't know what caused it and you aren't sure how you fixed it. I was using the ESV today and went to link it to another Bible. When I clicked on the little arrow to reveal the drop down menu, both the linking menu and the font size where missing. (see below)

Nothing I did would reveal the menu. So I moved the ESV over to another panel in my layout and it appeared. When I moved it back to it's original spot, it was now displaying the menu correctly. (see the below) I don't know why this fixed it, but unless I am missing something, this appears to be a bug. It's not a big deal, but rather a minor annoyance.
