TIFF icons won't display
The image icons for hundreds of my TIFF files only show the generic TIFF icon, and not the file image. I am running Sierra 10.12.5 I can't find any thread that relates to this problem with this newest version of the OS. Old advice is irrelevant, as there is not com.apple.finder.plist file, or any com.apple.desktop.plist file, and etc. I just this minute ran the update on the OS and no joy there. Any thoughts? Most vexing having to open large files just to get a hint of what they are.
MacBook Pro, macOS Sierra (10.12.5)