I had a similar situation in one of my AS campaigns. I used ForceDiplomacy to get all settlements of the Romans for one turn and gave them back afterwards. This saved my game.

Maybe you want to try that out?

If it is at the end of the roman turn (or at the beginning of the next faction (which I'm not quite sure who that is)) you have to try that with this faction.

XSamatan

PS: Your savegame crashes on my build instantly, maybe someone else can try?