Hi, 

I am getting this error on an Episerver 7 site on our test server, the exact same files works locally (same db, vpp etc). It only appears when I try to edit a property with the type LinkItemCollection. I have tried other sites on the same server with the same episerver version, and their LinkItemCollection properties works fine.

I have tried looking at all the module.config's I can find, but can't see anything suspicious. Any ideas?

StackTrace:

[ArgumentException: An item with the same key has already been added.]
   System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +14493519
   EPiServer.Shell.Web.Mvc.Html.DojoExtensions.DojoConfig(Page page, Boolean parseOnLoad, Boolean registerModulePaths, Boolean async) +666
   ASP.secure_cms_edit_editproperty_aspx.__Render__control2(HtmlTextWriter __w, Control parameterContainer) in E:\***\EditProperty.aspx:7
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +131
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +150
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +246
   System.Web.UI.HtmlControls.HtmlHead.RenderChildren(HtmlTextWriter writer) +28
   System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer) +49
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +150
   ASP.secure_cms_masterpages_episerverui_master.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in E:\Sites\E***\secure\CMS\MasterPages\EPiServerUI.Master:10
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +131
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +150
   System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +246
   System.Web.UI.Page.Render(HtmlTextWriter writer) +40
   System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +150
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5363