Preview no longer working in Photos with shift key
Used to be able to select a photo in Photos and hit the shift key to generate a preview. No longer working in Mojave. I tried repairing the Photos library, no go. Also tried deleting cache.db files in QuickLookDaemon, no go. Very frustrating!!!!!
iMac, macOS Mojave (10.14.1), 2.66 GHz Intel Core 2 Duo (2010)