Ok, thats easy. You must have deleted one of the tow INS sounds that are autoloaded after the 2011 update (Ital strat is one, I don't recall the other). This presumably means you do not need to autoload that sound, in which case you may as well turn it off.

Press the RAM INS button.
scroll down to the RBK file (probably UPDATE_STYLE.RBK
press the EDIT button
Press F8 to turn autoload OFF.
then I think:
press save and then custom startup.

Reboot the audya, the error should be gone. If you want to use autoload its on page 98 of the latest manual (download from ketron.it)