I use Preview and Skim every single day for hours a day working on documents. I always set System Preferences to General, Recent Items 10. EC infallibly changes my settings back to Recent Items None. Some of the technical sites say "The .plist file is corrupted. Go to Library/Preferences and drag the file named com.apple.recentitems.plist into the Trash and empty it. When you open System Preferences again a new com.apple.recentitems.plist file will be created and you should be able to change the number of Recent Items without issue." Is there no easier way of dealing with this ? And why is this file becoming corrupted ? Is there nothing that I can do to prevent this from happening ?