Ahh, yeah - that would be the problem. Sorry, I always assume people are up to date :P The "naughty fun with Aura" was added in 0.15.3 (and CK is up to 0.16.6 now!) so you'll have to update.
You won't lose your saves or anything - the game automatically detects saves from previous versions. You just need to download, extract and play :)