I've had exactly the same error.
There is a solution https://bugs.launchpad.net/linuxmint/+bug/868802
But I've got these warnings in console:
dpkg: warning: downgrading gstreamer0.10-ffmpeg from 1:0.10.11-4.1 to 0.10.11-4.
dpkg: warning: downgrading libavformat52 from 5:0.6.3-0.0 to 4:0.6.2-5.
dpkg: warning: downgrading libavcodec52 from 5:0.6.3-0.0 to 4:0.6.2-5.
dpkg: warning: downgrading libavutil50 from 5:0.6.3-0.0 to 4:0.6.2-5.
Are these packages important?
Actually I've tried to push Refresh button in Update Manager and cannot see them in list of packages that should be updated.