I am trying to use side-by-side full screen mode in El Capitan. I honestly don't know if I am missing something or if it does not work for me. If I click and hold down the green light button in the Safari menu bar, I do not see a way to pick a side of the screen. I can either let it go or continue to hold. Dragging seems to have no effect.
I see these messages in the Console, making me think that something is not working properly:
6/10/15 10:09:49.002 AM WindowServer[200]: _CGXRemoveWindowFromWindowMovementGroup: window 0x33c is not attached to window 0x33e 6/10/15 10:09:55.407 AM WindowServer[200]: _CGXRemoveWindowFromWindowMovementGroup: window 0x33c is not attached to window 0x33e 6/10/15 10:09:58.800 AM WindowServer[200]: _CGXRemoveWindowFromWindowMovementGroup: window 0x33c is not attached to window 0x33e
John