I'm not sure what happened but I noticed recently that the Cover Flow icon previews were missing from my files in Finder. I'm using OSX 10.6.7. See the screenshot below - I'm expecting a preview of the file to be shown rather than the black document icon.
How can I get the preview back? The View Options have "Show Icon Preview" ticked.
Quicklook still works on individual files, just not in Finder.
Error message reported in Console:
/System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd: /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd: cannot execute binary file
(com.apple.quicklook): Exited with exit code: 126
Edit 2 Output of command suggested by @jm666
lipo -detailed_info /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd
lipo: can't figure out the architecture type of: /System/Library/Frameworks/QuickLook.framework/Resources/quicklookd.app/Contents/MacOS/quicklookd
After seeing the error message, I restored the previous version of quicklookd from my Time Machine backup and the problem was resolved. I'm going to do a clean install of Snow Leopard just to make sure there are no other issues with my system.