Crystal viewer control

[colin]

Hi All,

I have written a small web app that opens a report based on what the user selects from a pull down list. This works fine if it is a static report but when I use a report where you can select the refresh button to change the value of that report i.e. dates or loacations i get the following error:

Value null was found where an instance of an object was required.
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: Value null was found where an instance of an object was required.

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 identifed using the exception stack trace below.

Stack Trace:


[NullReferenceException: Value null was found where an instance of an object was required.]
CrystalDecisions.Web.ReportAgent.Refresh() +8
CrystalDecisions.Web.ViewerToolbar.OnRefresh(Object source, ViewerEventArgs e) +108
CrystalDecisions.Web.ViewerToolbar.OnRefreshInternal(CommandEventArgs e) +29
CrystalDecisions.Web.ViewerToolbar.OnBubbleEvent(Object source, EventArgs e) +580
System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +26
System.Web.UI.WebControls.ImageButton.OnCommand(CommandEventArgs e) +121
System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +127
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain() +660



Can anyone point me in the right direction as I am at the scratching my head stage at the moment.

Cheers

Colin

[schuurke28]

can you trap the error?
i.e.:

try
 'your code
catch 
 msgbox err.description
end try

hopefully this will give you a more specific errordescription.