The "Use email address as username" option appears to be broken in this build. I just installed a new DNN site, and usually enable this option, however after doing so was unable to register new users, and had an exception in the site log.

Message:Object reference not set to an instance of an object.

StackTrace:

InnerMessage:Object reference not set to an instance of an object.

InnerStackTrace:

at DotNetNuke.Modules.Admin.Users.Register.Validate() at DotNetNuke.Modules.Admin.Users.Register.registerButton_Click(Object sender, EventArgs e) at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e) at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)