Before files such as .docx files would show the text instead of just a blank page when you saw the file in a folder or on the desktop. Does it no longer do this after upgrading?
My m4a files just started not showing the preview pic on the icon with 10.13.1, (generic music icon like above post) although only the newly created ones. The older ones still show it. Odd.
As someone who has never owned a non-Apple computer (going back to the '80s) or non-Apple smart phone, it's really disappointing the extent to which Apple's quality control has slipped. Bugs in new features are one thing, but it's inexcusable for existing functionality to have such obvious bugs. But at least we have 75 new emojis.
Showing previews in the Finder was an existing functionality for years. How could no one at Apple notice it wasn't working before releasing this "upgrade" to the masses?