Little blue & white question mark
From time to time when I open a window (web site, email, etc.) I will get a small blue/white square with a question mark in it. I click on it, but nothing happens and I have been unable to figure out what to do with them other than ignore them. Seems I should be seeing something... what do I do with them.
MACBOOK PRO (RETINA, 15-INCH, LATE 2013), OS X Mavericks (10.9)