In UserPortal, after signing out, there are some NPEs thrown periodically within the login section, until the user logs in again.

This is because UserPortal's main models [UPBasicListModel, UPListModel, UPTemplateListModel] don't have their refresh timers stopped upon logout.

In WebAdmin, this is achieved via CommonModel, which calls EnsureAsyncSearchStopped on its main models. In UserPortal, there is no CommonModel, and therefore we need to call EnsureAsyncSearchStopped manually on UserPortal main models.