Would be happy to help, only I also get the "required DLC is not activated" and I do have G+K.
What other dlc might effect the game I don't know, my guess is civ logs all dlc available on the computer in each save game no matter whether the current game/mod uses them or not and wont load the game on an installation with out them. If that is the case it might be an idea to try to get a test save from an installation with a minimal amount of dlc so that as many as possible can test it.
Edit,
It seems I was correct, pressing the dlc button for the Greece game (see attachment) shows it needing
Genghis Khan's Mongolia
Harald Bluetooth's Denmark
Sejong The Great's Korea
Wonders o the Ancient world
Gods & Kings Expansion pack
Upgrade Date 1
What other dlc might effect the game I don't know, my guess is civ logs all dlc available on the computer in each save game no matter whether the current game/mod uses them or not and wont load the game on an installation with out them. If that is the case it might be an idea to try to get a test save from an installation with a minimal amount of dlc so that as many as possible can test it.
Edit,
It seems I was correct, pressing the dlc button for the Greece game (see attachment) shows it needing
Genghis Khan's Mongolia
Harald Bluetooth's Denmark
Sejong The Great's Korea
Wonders o the Ancient world
Gods & Kings Expansion pack
Upgrade Date 1