Hi All,

I have problem with the DNN site. It use version 05.04.01 (26).

The error said about "An item with the same key has already been added".

This is happen when I want to preview the page from backend.

If I create a new page and then I want to preview the page, it show the same error. But, if I create new page with copy the content from the current page, it can work properly. Would you please advice how to fix this error?

Thank you for your help before :)

Below is the error that appear on the site:

Server Error in '/' Application.
An item with the same key has already been added.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentException: An item with the same key has already been added.

Source Error:

The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL:

1. Add a "Debug=true" directive at the top of the file that generated the error. Example:

  <%@ Page Language="C#" Debug="true" %>

or:

2) Add the following section to the configuration file of your application:

<configuration>
   <system.web>
       <compilation debug="true"/>
   </system.web>
</configuration>

Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode.

Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario.

Stack Trace:

[ArgumentException: An item with the same key has already been added.]
   System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +51
   System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +7462172
   DotNetNuke.UI.ControlPanel.AddModule.LoadPaneModulesList() +308
   DotNetNuke.UI.ControlPanel.AddModule.LoadAllLists() +55
   DotNetNuke.UI.ControlPanel.AddModule.Page_Load(Object sender, EventArgs e) +422

[ModuleLoadException: An error has occurred.]
   DotNetNuke.Services.Exceptions.Exceptions.ProcessModuleLoadException(String FriendlyMessage, Control ctrl, Exception exc, Boolean DisplayErrorMessage) +381
   DotNetNuke.Services.Exceptions.Exceptions.ProcessModuleLoadException(Control ctrl, Exception exc, Boolean DisplayErrorMessage) +185
   DotNetNuke.Services.Exceptions.Exceptions.ProcessModuleLoadException(Control ctrl, Exception exc) +34
   DotNetNuke.UI.ControlPanel.AddModule.Page_Load(Object sender, EventArgs e) +444
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Control.AddedControl(Control control, Int32 index) +265
   System.Web.UI.ControlCollection.Add(Control child) +80
   System.Web.UI.Control.AddParsedSubObject(Object obj) +41
   System.Web.UI.Control.System.Web.UI.IParserAccessor.AddParsedSubObject(Object obj) +10
   ASP.admin_controlpanel_ribbonbar_ascx.__BuildControl__control16(Control __ctrl) +64
   System.Web.UI.CompiledTemplateBuilder.InstantiateIn(Control container) +12
   DotNetNuke.Web.UI.WebControls.DnnRibbonBarGroup.CreateChildControls() +515
   System.Web.UI.Control.EnsureChildControls() +87
   System.Web.UI.Control.PreRenderRecursiveInternal() +44
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842

[PageLoadException: An error has occurred.]
   DotNetNuke.Services.Exceptions.Exceptions.ProcessPageLoadException(Exception exc, String URL) +277
   DotNetNuke.Framework.PageBase.OnError(EventArgs e) +394
   System.Web.UI.Page.HandleError(Exception e) +84
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6776
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +242
   System.Web.UI.Page.ProcessRequest() +80
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21
   System.Web.UI.Page.ProcessRequest(HttpContext context) +49
   ASP.default_aspx.ProcessRequest(HttpContext context) +4
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75