I'm trying to start some of the new character stories, but for some reason, I get an error every time I start the card battles. I tried pressing ignore, but it just causes the cards in my deck to be deleted, making it so I can't win the battles. I think the last version I had played was 1.3, so my guess is the update syncer thing isn't working properly. I know it said it was buggy, but I can't continue playing at all if I can't enter battles with my cards.
0.13 to 0.18 is a big jump in content and system changes. Sorry the old version isn't working, if you REALLY don't want to start a new, fresh save and want to continue from where you left off. I suggest updating the game in increments. eg. 0.13 > 0.15 > 0.17 > 0.18. Play a card battle with each update to make sure things are working properly and make a new save file.
You can find all the previous versions here: