Hi, Anyone here use : Telerik Report(version 4.2.10.1221) using Silverlight 4.0 AND Telerik Report Viewer AND Authentification? My problem is after few minutes using my application all DomainService (decorated with [RequiresAuthentication]) become "Denied". Of course, localy everyting work fine... I suspect the sessionstate and I change sessionState mode="SQLServer" (with all the things is needed). Same error. Maybe my application use too much ressources (like memory) on the server?BUT I try with a very simple report 1 row and 3 fields and same error. Everything work fine when I remove the report class of the solution (without report ) Any clue or idea will be very appreciate since I am on this case since 2 weeks!