I cannot access NON-US child portals after upgrade to DNN 5.4.1. Below is the error:
 I don't have any ideas. Any help would be appreciated..

AssemblyVersion: 5.4.1
PortalID: 5
PortalName: 
UserID: -1
UserName: 
ActiveTabID: -1
ActiveTabName: 
RawURL: /Default.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: 
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Chrome/4.1.249.1064 Safari/532.5
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 2115e8b0-5751-4b68-bc30-61456e4b4a9e
InnerException: Object reference not set to an instance of an object.
FileName: 
FileLineNumber: 0
FileColumnNumber: 0
Method: DotNetNuke.Framework.DefaultPage.InitializePage
StackTrace: 
Message: DotNetNuke.Services.Exceptions.PageLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Framework.DefaultPage.InitializePage() at DotNetNuke.Framework.DefaultPage.Page_Init(Object sender, EventArgs e) at System.Web.UI.Control.OnInit(EventArgs e) at System.Web.UI.Page.OnInit(EventArgs e) at DotNetNuke.Framework.PageBase.OnInit(EventArgs e) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---

virtual directory

Is this a bug in DNN 5.4.1? Is it not recommended to upgrade to 5.4.1 for now? Sorry, its not just non-us portal but all child portals. Only portal/0 (main portal) is working fine. Some of those child portals even are not visible on Host > Portals. The rest can be accessed, but after user login then it thrown an error: An error has occurred. DotNetNuke.Services.Exceptions.PageLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Framework.DefaultPage.InitializePage() at DotNetNuke.Framework.DefaultPage.Page_Init(Object sender, EventArgs e) at System.Web.UI.Control.OnInit(EventArgs e) at System.Web.UI.Page.OnInit(EventArgs e) at DotNetNuke.Framework.PageBase.OnInit(EventArgs e) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---