Looking for Error 60 on Google it's generally a reading error between the changer and the head unit. Suggestions ranged from checking with the manufacturer of the unit to possibly being the head unit as well.

I personally would search Pioneer's website for your model number of the changer and see if your are able to find the Error 60 code in their reference manual.

That's my best suggestion. Sorry I could not be more specific without knowing the model number of changer you have.