Taken from Somkas patchnote for V14: Since a lot of old content has been changed, saves from previous versions will not work!(I know how you don't like to replay the game from the beginning because of the new content, but starting from the next versions, saving from previous versions (starting from this one) should work again. This is due to the fact that the content that is in the middle of the game has been redone and the logic of quests has been changed, and even if we could make the saving from the old ones work without errors, it would not make sense since you would miss part of the new content.
Hope this helps