There was a problem with three ensemble presets for the original Garritan Personal Orchestra 5 (GPO5) installer that caused the ARIA Player to look in the wrong place for some of the Solo String instruments.  This resulted in an error which states that an instrument "was not found!" 


You can fix this by reinstalling the Garritan Personal Orchestra 5 library using the updated installer from your MakeMusic account. Once you have finished downloading the installer package, please run the full, default installer (including the ARIA Player portion). The installer should appear in your Downloads folder by default.