Calibre isn't opening

I'm running 7.22 64 bit on Windows 10.

When I try to launch, Calibre appears in my toolbar, but I can't actually get it to open. When I hover over the icon to see the mini window, it shows up a blank white tile.

I've tried uninstalling and reinstalling; I've tried installing previous versions; I've tried running as admin; I've tried opening it without antivirus.

I can open books from the directory; I can even add books to the library by "opening with calibre program". I just can't seem to access the actual calibre user interface.

Help?