This fixed it. Thanks for the help.No issues here. Check if your m4r files are actually there. It happened to me once when upgrading from 6.1.3 to 6.1.4, and it turned out the m4r files disappeared somehow. The link within itunes was there, and they even appeared in the tone sync screen, but the actual files were missing.
Recreate them, add them to itunes and resync. It should work.