When trying to use the Ektron Redirect Module in a Three Tier environment, this error is thrown as an exception.
The current type, Ektron.Cms.Settings.UrlAliasing.IRedirectManager, is an interface and cannot be constructed. Are you missing a type mapping?
Redirects are not currently available in Three-Tier. The service client for the manager is not built at this time. This is being added as a feature request for a future release.
Custom redirects outside the scope of Ektron would need to be implemented if required.