How to resolve a stack trace in visual studio 2008

Question

Hi, I'm developing an ASP.NET website in viusal studio 2008, the thing is that I changed a line in the code, this change trows an exception (NullReferenceException) at runtime, after I change the line back it still trows the same exception, I want to follow the stack trace to look into the error and solve it, can you guys give some tips? thanks.

EDIT: Im developing a Web Map Aplication with ArcGis Server 9.3.1, Here's the stack trace:

[NullReferenceException: Referencia a objeto no establecida como instancia de un objeto.]
   ESRI.ArcGIS.ADF.Web.UI.WebControls.DataSourceManager.AddDataSourceInstance(String type, String name, String identity, String definition) +666
   ESRI.ArcGIS.ADF.Web.UI.WebControls.MapResourceItem.CreateResource() +404
   ESRI.ArcGIS.ADF.Web.UI.WebControls.GISResourceManager`2.initResourceItems() +170
   ESRI.ArcGIS.ADF.Web.UI.WebControls.GISResourceManager`2.OnInit(EventArgs e) +149
   System.Web.UI.Control.InitRecursive(Control namingContainer) +333
   System.Web.UI.Control.InitRecursive(Control namingContainer) +210
   System.Web.UI.Control.InitRecursive(Control namingContainer) +210
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +378

Answer 1

• Maybe assembly was not reloaded if it thows the same exception while code is changed back?
• could be about data or configuration
• if you do not have a source code, you can not follow the stack trace in debug

Answer 2

You should also do a Clean Solution (from the Build menu). This will remove any compilations that it is caching for the ASP.Net page.