In the last few weeks, every time I double click a file to open it, i get a Finder message "The application can't be found." I get it with PDFs (have Acrobat), Word, Excel, Powerpoint (Office 2013 installed). In the Finder window it recognizes the file type and lists the application, but it will not open it. I looked but could not find a file/application association preference in Finder. I am running OSX 10.9.4. Any ideas?