Canon CR2 files no longer viewable in Finder
I shoot with a Canon 5D Mark III in raw format only. This results in a .CR2 file, Canon's defacto file appendage. This camera is listed as being supported by El Capitan according to this link: Digital camera RAW formats supported by OS X El Capitan - Apple Support
However, when I highlight a file in the Finder window, I now longer get an image preview, just a file logo. The same thing happens if I try to preview the file using the space bar. This is incredibly frustrating since I can no longer tell which images I have downloaded off a CF card or make a selection from a group of images.
How do I fix this? Is it a common problem? Everything worked fine with Yosemite.
I'm using a 2013 Mac Pro if it makes any difference.
Mac Pro, OS X El Capitan (10.11.1)