Can someone tell me why the following code won't work? I've verified the the UserInfo object is not null but it still throws "No user specified. You must initialize the UserInfo property of the tree provider."
UserInfo ui = UserInfoProvider.GetUserInfo("administrator");
CMS.TreeEngine.TreeProvider tree = new CMS.TreeEngine.TreeProvider(ui);
string aliasPath = String.Format("/Events-and-Awards/Events");
CMS.TreeEngine.TreeNode sessionNode = tree.SelectSingleNode("CorporateSite", aliasPath, "en-us");
sessionNode.SetValue("Title", aiSession.Title);
sessionNode.SetValue("Code", aiSession.Code);
sessionNode.SetValue("description", aiSession.SessionDescription);
sessionNode.Update();