All my Folder and Application icons disappeared in Finder
I was having a similar problem--not with icons in the dock--but Illustrator icons in Finder list view would just display as blank white icons instead of the Illustrator CC icons.  Using the info in this thread, I showed all hidden files.  This can be done using the XtraFinder app.  Once all hidden files were shown, I went to the path below and moved the store.index file to the desktop and logged out and logged back in.  The store.index file re-created itself and all of my Illustrator icons were back.  You can delete the one on the desktop and empty the trash before once again hiding all the hidden files through XtraFinder.  Solved!

HD/private/var/folders/*/*/C/com.apple.iconservices/store.index

The asterisks represent random folder names that are different for each computer.  The last asterisk may have more than one folder.  Find the C folder that is not locked.