Open bug in Launchpad.net:
https://bugs.launchpad.net/bugs/796173

$ mount
/dev/sda5 on / type ext4 (rw,errors=remount-ro,commit=0)
proc on /proc type proc (rw,noexec,nosuid,nodev)
none on /sys type sysfs (rw,noexec,nosuid,nodev)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
none on /dev type devtmpfs (rw,mode=0755)
none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
none on /dev/shm type tmpfs (rw,nosuid,nodev)
none on /var/run type tmpfs (rw,nosuid,mode=0755)
none on /var/lock type tmpfs (rw,noexec,nosuid,nodev)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
/dev/sda6 on /media/sda6_datos type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_permissions)
gvfs-fuse-daemon on /home/caravena/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=caravena)

My music in /media/sda6_datos

Solution: mount /media/sda6_datos and start banshee

An unhandled exception was thrown: Could not read add-in description

  at Mono.Addins.Addin.get_Description () [0x00000] in <filename unknown>:0
  at Mono.Addins.Database.AddinDatabase.InternalGetInstalledAddins (System.String domain, System.String idFilter, AddinSearchFlagsInternal type) [0x00000] in <filename unknown>:0
  at Mono.Addins.Database.AddinDatabase.InternalGetInstalledAddins (System.String domain, AddinSearchFlagsInternal type) [0x00000] in <filename unknown>:0
  at Mono.Addins.Database.AddinDatabase.Update (IProgressStatus monitor, System.String domain) [0x00000] in <filename unknown>:0
  at Mono.Addins.Database.AddinDatabase.Repair (IProgressStatus monitor, System.String domain) [0x00000] in <filename unknown>:0
  at Mono.Addins.AddinRegistry.Rebuild (IProgressStatus monitor) [0x00000] in <filename unknown>:0
  at Banshee.ServiceStack.ServiceManager.InitializeAddins () [0x00000] in <filename unknown>:0
  at Banshee.ServiceStack.ServiceManager.DefaultInitialize () [0x00000] in <filename unknown>:0
  at Banshee.ServiceStack.Application.Initialize () [0x00000] in <filename unknown>:0
  at Banshee.Gui.GtkBaseClient.Initialize (Boolean registerCommonServices) [0x00000] in <filename unknown>:0
  at Banshee.Gui.GtkBaseClient..ctor (Boolean initializeDefault, System.String defaultIconName) [0x00000] in <filename unknown>:0
  at Banshee.Gui.GtkBaseClient..ctor () [0x00000] in <filename unknown>:0
  at Nereid.Client..ctor () [0x00000] in <filename unknown>:0
  at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
Exception has been thrown by the target of an invocation.

  at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.ConstructorInfo.Invoke (System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type) [0x00000] in <filename unknown>:0
  at Banshee.Gui.GtkBaseClient.Startup () [0x00000] in <filename unknown>:0
  at Hyena.Gui.CleanRoomStartup.Startup (Hyena.Gui.StartupInvocationHandler startup) [0x00000] in <filename unknown>:0

Banshee-debug-log.txt:
https://bugs.launchpad.net/ubuntu/+source/banshee/+bug/796173/+attachment/2166241/+files/banshee-debug-log.txt