What: A blank window still remains or is displayed after closing out the Library or Collection.
How to re-produce:
1. Open the Library or Collection tool as a floating window. Maximize this window.
2. For the Collection tool, open any collection you have.
3. Close the Library or Collection window.
You can then swipe up on the trackpad to view Mission Control and you will see the blank window. See below.
Logos 6 SR-1 on OS X 10.10
David
