No, you did not get these versions by checking out the OpenACS 5.6 tree.
i am this week completely booked out, so i have no chance to look deeper into your problem. But still, i am wondering: is this a fresh installation? You seem to have very few folders and in particular, no xowiki folders. Is this correct? It looks to me as if xowiki tries to create a new folder but fails for some reason.