I was affected by this bug, too.
The "rhythmbox-plugins" package was correctly installed by default with my Ubuntu 14.04 installation.
rhythmbox: Installed: 3.0.2-0ubuntu2 rhythmbox-plugins: Installed: 3.0.2-0ubuntu2
Going to "Tools" -> "Plugins ..." and enabling " MPRIS D-Bus Interface" ( restarting Rythmbox afterwards ) fixed the issue for me.
I was affected by this bug, too.
The "rhythmbox-plugins" package was correctly installed by default with my Ubuntu 14.04 installation.
rhythmbox: plugins:
Installed: 3.0.2-0ubuntu2
rhythmbox-
Installed: 3.0.2-0ubuntu2
Going to "Tools" -> "Plugins ..." and enabling " MPRIS D-Bus Interface" ( restarting Rythmbox afterwards ) fixed the issue for me.