Event log has an error. “An unhandled exception has occurred”

Question

I am using Visual Studio 2005 and IIS 6.0.. I have this warning in the event log. I am trying to find what it is. I have never went through this exception when i am working. What can be done and where can be done to not get the exception warning again. Thanks so much in advance!!

Event code: 3005 
Event message: An unhandled exception has occurred. 
Event time: 10/13/2010 3:20:26 PM 
Event time (UTC): 10/13/2010 7:20:26 PM 
Event ID: fba7eb72412b4383a4c94bfcfd5c81a1 
Event sequence: 708 
Event occurrence: 6 
Event detail code: 0 

Application information: 
    Application domain: /LM/W3SVC/568802591/Root-1-129314697219905000 
    Trust level: Full 
    Application Virtual Path: / 
    Application Path: C:\Inetpub\wwwroot\kjdfd.live\ 
    Machine name: VME1053 

Process information: 
    Process ID: 472 
    Process name: w3wp.exe 
    Account name: NT AUTHORITY\NETWORK SERVICE 

Exception information: 
    Exception type: NullReferenceException 
    Exception message: Object reference not set to an instance of an object. 

Request information: 
    Request URL: https://www.kjdfd.com:443/UserTownPage.aspx?tid=0 
    Request path: /UserTownPage.aspx 
    User host address: 173.188.124.86 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: NT AUTHORITY\NETWORK SERVICE 

Thread information: 
    Thread ID: 11 
    Thread account name: NT AUTHORITY\NETWORK SERVICE 
    Is impersonating: False 
    Stack trace:    at UserTownPage.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)


Custom event details: 

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Page Load:

protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            SearchType = CommonHelper.SearchInnerType.Distance;
            MakeActive(SearchType);
            LoadData(true);
        }
    }

private void MakeActive(CommonHelper.SearchInnerType sType)
    {
        DealsActive.Attributes.Remove("class");
        PopularActive.Attributes.Remove("class");
        DistanceActive.Attributes.Remove("class");
        AZActive.Attributes.Remove("class");
        switch (sType)
        {
            case CommonHelper.SearchInnerType.A_Z:
                AZActive.Attributes.Add("class", "current");
                break;
            case CommonHelper.SearchInnerType.Distance:
                DistanceActive.Attributes.Add("class", "current");
                break;
            case CommonHelper.SearchInnerType.Popular:
                PopularActive.Attributes.Add("class", "current");
                break;
            case CommonHelper.SearchInnerType.Deals:
                DealsActive.Attributes.Add("class", "current");
                break;
            default:
                AZActive.Attributes.Add("class", "current");
                break;
        }

    }



private void LoadData(bool isSetPageIndex)
    {
        if (Session["keyword"] != null && Session["city"] != null && Session["state"] != null
            && Session["zipcode"] != null && Session["radius"] != null && Session["category"] != null)
        {
            string keyword = Session["keyword"].ToString();
            string city = Session["city"].ToString();
            string state = Session["state"].ToString();
            string zipCode = Session["zipcode"].ToString();
            double radius = Convert.ToDouble(Session["radius"].ToString());
            int categoryID = Convert.ToInt32(Session["category"].ToString());
            if (isSetPageIndex) PageIndex = 1;
            DisplayRecords(keyword, city, state, zipCode, radius, categoryID, 1);
        }
    }

Answer 1

The problem appears to be a NullReferenceException is being thrown insed the Page_Load method of the UserTownPage type. More than that is not determinable from the information provided.

What you'll need to do is debug into that method and see exactly where the null reference is occuring.