1) In VS.NET go to the Debug Menu >> 'Exceptions...' >> 'Common Language Runtime Exceptions' >> 'System' and select 'System.NullReferenceException' 2) In the bottom of that dialog there is a 'When the exception is thrown:' group box, select 'Break into the debugger' 3) Run your scenario. When the exception is thrown, the debugger will stop and notify you with a dialog that says something like: 'An exception of type 'System.NullReferenceException' has been thrown. [Break] [Continue]' Hit [Break]. This will put you on the line of code that’s causing the problem.
(from sburke_online@microsoft..nospam..com on microsoft.public.dotnet.framework.windowsforms)