I’m receiving this error when trying to load my saved files “map file reference by the saved game is different from the map file on hard drive”.
I’m getting the same issue as well trying to load any of my saves for “The Fall of Silvermoon” and “Key of the Three Moons”. My saves for the two missions before that (“Into the Realm Eternal” and “Digging Up the Dead”) seem to work though, but then I get the error for “Frostmourne”. Did some of the campaign maps get renamed?