Related Clues:

• Trial's companion
• "File not found," for example
• Bug, perhaps
• Shortstop's blunder
• "File not found," e.g.
• Misapprehension
• Bloomer
• 'Does not compute'
• Ground ball between the legs, for one
• Eraser's target
• Mistake, lapse
• Blunder or mistake
• It's a mistake
• Blunder, slip
• Mistake of terrorist