Today, my Mac crashed with a kernel panic. After rebooting I tried to start iTunes but it just showed this error message:
iTunes application could not be opened. An unknown error occurred (13010).

I remembered that I was in the process of updating the iTunes Genius database when the kernel panic occurred. I was able to start iTunes again after deleting the iTunes Library Genius.itdb file. You’ll find the Genius database file in the direcory $HOME/Music/iTunes.