Server Error in '/' Application.

Value cannot be null.
Parameter name: source

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.ArgumentNullException: Value cannot be null.
Parameter name: source

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:


[ArgumentNullException: Value cannot be null. Parameter name: source] System.Linq.Enumerable.Where(IEnumerable`1 source, Func`2 predicate) +6295698 controls_MainCats.GetSubSubCategories(Cats catItem, Int32 fatherId) +553 controls_MainCats.GetDropDownMenu(Cats item, Boolean menu) +579 ASP.controls_maincats_ascx.__DataBind__control4(Object sender, EventArgs e) +615 System.Web.UI.Control.OnDataBinding(EventArgs e) +100 System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) +178 System.Web.UI.Control.DataBindChildren() +248 System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) +195 System.Web.UI.WebControls.Repeater.CreateItem(Int32 itemIndex, ListItemType itemType, Boolean dataBind, Object dataItem) +174 System.Web.UI.WebControls.Repeater.AddDataItemsIntoItemsArray(IEnumerable dataSource, Boolean useDataSource) +291 System.Web.UI.WebControls.Repeater.PostGetDataAction(IEnumerable dataSource) +109 System.Web.UI.WebControls.Repeater.OnDataBinding(EventArgs e) +81 System.Web.UI.WebControls.Repeater.EnsureDataBound() +143 System.Web.UI.WebControls.Repeater.OnPreRender(EventArgs e) +21 System.Web.UI.Control.PreRenderRecursiveInternal() +132 System.Web.UI.Control.PreRenderRecursiveInternal() +227 System.Web.UI.Control.PreRenderRecursiveInternal() +227 System.Web.UI.Control.PreRenderRecursiveInternal() +227 System.Web.UI.Control.PreRenderRecursiveInternal() +227 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3671


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4110.0