With the small amount of information you have provided I would suggest you open Print & Scan and remove the current MP560 printer. Once removed, then select to add it again and see if this gets you printing again.
If this does not help then please reply with more information about how the MP560 is connected to your Mac and whether it was working previously.
Please see my detailed posting regarding this, about halfway down the page from this link
Believe you may be the same situation. It is a Canon problem.