Fremantle
I don't quite know what's going wrong yet, but with two wikis now I've had the following error when trying to log in after upgrading to 1.34: "Auto-creation of a local account failed: Username entered already in use. Please choose a different name."
The error seems to go away after the session expires, and the user is logged in correctly (sometimes after a subsequent error of "Auto-creation of a local account failed: You have not specified a valid username.").