Server Error in '/' Application.

'DropDownList_Corsi' has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value

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.ArgumentOutOfRangeException: 'DropDownList_Corsi' has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value

Source Error:


Line 77:             DropDownList_Corsi.DataTextField = "LinguaNome"
Line 78:             DropDownList_Corsi.SelectedValue = Request("oid")
Line 79:             DropDownList_Corsi.DataBind()
Line 80:             DropDownList_Corsi.Items.Insert(0, New ListItem(Resources.Iscrizione.Seleziona, ""))
Line 81: 

Source File: C:\inetpub\wwwroot\IdeaVerona\PagineWeb\1\_171.aspx.vb    Line: 79

Stack Trace:


[ArgumentOutOfRangeException: 'DropDownList_Corsi' has a SelectedValue which is invalid because it does not exist in the list of items.
Parameter name: value]
   System.Web.UI.WebControls.ListControl.PerformDataBinding(IEnumerable dataSource) +2751548
   System.Web.UI.WebControls.ListControl.OnDataBinding(EventArgs e) +303
   System.Web.UI.WebControls.ListControl.PerformSelect() +38
   System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +76
   _171._171_Init(Object sender, EventArgs e) in C:\inetpub\wwwroot\IdeaVerona\PagineWeb\1\_171.aspx.vb:79
   System.EventHandler.Invoke(Object sender, EventArgs e) +0
   System.Web.UI.Control.OnInit(EventArgs e) +97
   System.Web.UI.Page.OnInit(EventArgs e) +14
   System.Web.UI.Control.InitRecursive(Control namingContainer) +142
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +416


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4700.0