title: Exception has been thrown by the target of an invocation - InvalidCastException in App_Code.dll
body: <p>I have an asp.net application in which I am receiving the following error message: -</p>
  
  <pre><code>Exception: System.Reflection.TargetInvocationException
  
  Message: Exception has been thrown by the target of an invocation.
  
  Stack Trace:
  at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct&amp; sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
  at System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
  at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
  at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
  at System.Web.UI.WebControls.ObjectDataSourceView.InvokeMethod(ObjectDataSourceMethod method, Boolean disposeInstance, Object&amp; instance)
  at System.Web.UI.WebControls.ObjectDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments)
  at System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback)
  at System.Web.UI.WebControls.DataBoundControl.PerformSelect()
  at System.Web.UI.WebControls.BaseDataBoundControl.DataBind()
  at System.Web.UI.WebControls.FormView.DataBind()
  at System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound()
  at System.Web.UI.WebControls.FormView.EnsureDataBound()
  at System.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls()
  at System.Web.UI.Control.EnsureChildControls()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Control.PreRenderRecursiveInternal()
  at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) 
  </code></pre>
  
  <p>In an effort to debug the error I have turned the EnablePartialRendering setting to false but this didn't help and the error was displayed in exactly the same way.</p>
  
  <p>The only clue I have is that in the Output window for Debug I am seeing this message: -
  'A first chance exception of type 'System.InvalidCastException' occurred in App_Code.iqmc5gba.dll'</p>
  
  <p>Whilst this indicates that the error is occurring within the code held in the App_Code folder I'm actually none the wiser as there are 211 files that would appear to be contributing to the content of the dll as they are all named App_Code.iqmc5gba.nnn.cs where nnn is a number between 0 and 210</p>
  
  <p>At the time ther error occurs the code is getting the data to display a record in a formview. <strong>The error only occurs on one record in the database that I can see at the moment.</strong></p>
  
  <p>Is anyone aware of any techniques that I can use to try and identify the line of code that is being executed at the point the invalidcastexception is encountered?</p>