I had to reinstall Windows. Before I did so, I backed up my Save game files. When I reinstalled 7 Days and put my save folder back in the appropriate place I found that although the game recognised what they were (3 different saves) it gave the following message to each: "This save game is for a world that no longer exists. "
My 7 Days was a bog standard one (20.6 b9) and me reinstall is the same - no mods.
Any ideas? Solutions?