Have reviewed your install and it's not working because you have too many duplicate categories. For some reason you have 2 of nearly every GJ forum category. This causes the alias to be duplicated, which Kunena will not allow. I've no idea how you ended up with duplicates, but you'll need to delete the duplicates so it can work again. If your GJ forum categories have no posts in them then just delete them all and navigate to GJ > Tools then click "Recreate All" in the forum check error.