Question

What would cause the Visual Studios debugger to ignore the breakpoints in the code behind of an aspx page and throw a null exception from a null session variable instead?

I’ve been trying to debug a session variable timeout issue but every time I run the debugger the null exception gets thrown instead of hitting the breakpoints (I have break points on page load as well as the button that should be triggering the postback).

Any ideas?

EDIT:

_reportEntity is a accessor/mutator property that is saving to a session variable:

Session["_PD_AR_reportEntity"]

This variable is initialized in the Page_Load when the user first arrives at the page and then is updated at each postback. We are saving an LLBL generated entity class to the session variable. Before the debug issue I was trying to debug why our session variable was being lost after 20 minutes of inactivity from the user since we have a similar module using the same techniques, app pool, and timeout settings (1440 minutes) and it does not lose its session variable after 20 minutes.

if this is a UI issue I need to bring up that we are using telerik AJAX controls, we have a RadAjaxLOadingPanel for partial postbacks and a RadMultiPage to deal with our tabstrip.

Here’s the information from the Null being thrown:

Server Error in '/Project_Direct/Secure/Modules/AnalyticReports' Application.
--------------------------------------------------------------------------------


 Object reference not set to an instance of an object. 
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.NullReferenceException: Object reference not set to an instance of an object.

Source Error: 
Line 2734:            {
Line 2735:                GridDataItem item = (GridDataItem)ddl.NamingContainer;
**Line 2736:                var foundAnalyte = _reportEntity.GetReportColumns.AsEnumerable().Where(x => x["Analyte"].ToString() == item["bndAnalyte"].Text).FirstOrDefault();**
Line 2737:                //string v = item["ParameterUnitsLookup"].Text;//ParameterUnits
Line 2738:                if (foundAnalyte == null) 

Stack Trace: 
[NullReferenceException: Object reference not set to an instance of an object.]
   Trihydro.ProjectDirect.Modules.AnalyticReports.TabView.ddlAnalyteUnit_PreRender(Object o, EventArgs e) in C:\TFSWorkspaceKEllington\Trihydro_IPortal\Modules\AnalyticReports\TabView.aspx.cs:2736
   System.Web.UI.Control.OnPreRender(EventArgs e) [phone]
   System.Web.UI.WebControls.ListControl.OnPreRender(EventArgs e) +41
   System.Web.UI.Control.PreRenderRecursiveInternal() +107
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Control.PreRenderRecursiveInternal() +223
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3393



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Version Information: Microsoft .NET Framework Version:2.0.50727.5456; ASP.NET Version:2.0.50727.5456 

Answer 1

I’m going to close this as I’m on new tasks now.

I’m 90% sure that the underlying issue causing all of this is that our IIS 7 settings have our Idle-Timeout set to 20 minutes which is causing our session variable to die and cause our null issues which cause this behavior in the debugger. Thank you for your help in this matter JWJones.