Grid view is not available, either from G shortcut, or from drop-down menu, or from icon on screen. Only shows the single selected image.
Other views (loupe, compare, survey..) all work.
It used to work fine.
I've rebooted, and re-installed the app- still no grid view.
In Library, do View > Decrease Grid Size several times.
If that doesn't help, try resetting LR's preferences: http://www.lightroomforums.net/showthread.php?25197-Resetting-the-lightroom-preferences-fi le-updated
Thanks very much- the solution was indeed that simple!