http://www.camerahacker.com/Forums/DisplayComments.php?file=Video%20Camera/Sony/Sony_DCR-TRV18_-_Error_Code..html This site believes in physical discipline for your camera. It seems to work well.

Possibly the tape is dodgy. Perhaps from extreme temperatures. I got this message and a different tape fixed it. I bought the tape New-second hand, un opened and perhaps it had a dodgy storage history. Have you had your camera in Very cold or hot temperatures. Sony hinted at this also. I have had mine in a perhaps -10+ degree climate.