Hello Experts,

i am using DOTNETNUKE Community edition( ver. 05.02.02)  in my website .

theb situation is that i have created three portals and named them as the roles used in my site. now i create a child portal for a user under the portal which suits the user role. when i create the child portal named as the users name some of the child portals are created and run successfully while in some child portals it throws an error as given below.

"

Server Error in '/Couple' Application.

---

Object reference not set to an instance of an object.

[NullReferenceException: Object reference not set to an instance of an object.]
   DotNetNuke.Entities.Portals.PortalSettings..ctor(Int32 tabID, PortalAliasInfo objPortalAliasInfo) in C:\CCNet_Builds\DotNetNuke_5_Maintenance\WorkingDirectory\Library\Entities\Portal\PortalSettings.vb:147
   DotNetNuke.HttpModules.UrlRewriteModule.OnBeginRequest(Object s, EventArgs e) in C:\CCNet_Builds\DotNetNuke_5_Maintenance\WorkingDirectory\Library\HttpModules\UrlRewrite\UrlRewriteModule.vb:476
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

and i am really stuck in finding out why the aforesaid error is thrown ...

please give me solutions to troubleshoot this error..

 it didnt worked whenever i create a child portal some of them work while on others i am redirected to default website.....

any solution....