Server Error in '/' Application.

A column named 'class' already belongs to this DataTable.

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.Data.DuplicateNameException: A column named 'class' already belongs to this DataTable.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[DuplicateNameException: A column named 'class' already belongs to this DataTable.] System.Data.DataColumnCollection.RegisterColumnName(String name, DataColumn column) +119 System.Data.DataColumnCollection.BaseAdd(DataColumn column) +103 System.Data.DataColumnCollection.AddAt(Int32 index, DataColumn column) +216 site.AreaWebsite.get_CitiesForFilter() in D:\a\1\s\TovtodaNew\Classes\AreaWebsite.cs:49 site.UC_Filters.GetAreaDT(Int32 _areaId) in D:\a\1\s\TovtodaNew\UC_Filters.ascx.cs:160 site.UC_Filters.Page_Load(Object sender, EventArgs e) in D:\a\1\s\TovtodaNew\UC_Filters.ascx.cs:93 System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +85 System.Web.UI.Control.OnLoad(EventArgs e) +79 System.Web.UI.Control.LoadRecursive() +130 System.Web.UI.Control.LoadRecursive() +200 System.Web.UI.Control.LoadRecursive() +200 System.Web.UI.Control.LoadRecursive() +200 System.Web.UI.Control.LoadRecursive() +200 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2852


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4690.0