Since upgrading to Hardy Heron I am no longer able to access my sound files through Amarok, Exaile or Rhythmbox. All three applications hang. In addition, I see messages saying "Stream not available. No URL." and similar messsages. Never happened before.

I checked my hardware set up and the sound system passes the test. Something is wrong with the configuration. Must be some files missing somewhere.

Can anyone point me in the right direction to resolving this issue?

Thank you.