If you have repos enabled other than the default Mint and Debian repos, you may have a dependency issue. I enabled Hadret's experimental PPA
so I could install nautilus-elementary and Gnome Global Menu. That repo contains a newer version of Transmission, but because LMDE is based on Debian Testing, some of my lib files don't meet the dependency requirements. I get that message every time, so I can't do a dist-upgrade from the command line. My work-around is to go to Synaptic, mark all upgrades, then search for Transmission, and un-select it. I can then run the rest of the updates, bypassing the Transmission upgrade.