I'm also experiencing start-up issues (Windows 10 Pro V1511, 64bit, I7-3930K 3.20GHz, 16Gb RAM, installed Fritzing this morning), though in my case the app starts up OK, but soon hangs.
The first time I started it up, I let it sit for quite a while and it eventually opened a query window about needing to remove some obsolete files in order to update. When I clicked.OK, Windows reported "not responding" and offered me the option to wait or close it (I closed it).
Subsequent start attempts brings up the main "Breadboard view" window, but the revolving hourglass icon seems to go on forever. Clicking on the Frtzing window yields "not responding"..