Exception that goes away with Clean/Rebuild. How to diagnose/prevent?

Question

Pre-Problem: our office was hit by a worm due to a corporate patching oversight, and the boys in the lab repaved my machine. I needed to re-install all my development tools (Visual Studio 2005, SP1, and the Web Application Project Setup patch) again. The following problem did not occur before this event.

I've been working on an ASP.NET web application project for several months now. I've been editing, debugging, etc without a problem. Then, I added a single line of code, ran it in Debug and got this error:

System.Web.HttpUnhandledException: 
Exception of type 'System.Web.HttpUnhandledException' 
was thrown. 
System.IO.FileLoadException: The given assembly name 
or codebase was invalid. (Exception from HRESULT: 0x80131047)

I uncommented the new code, built the project and ran in debug again, but got the same error.

New Code:

Me.frm.btnSubmitChanges.Attributes.Add("onclick", "javascript:return validateSubmit();")

The only way I've been able to fix this is to Clean, then Rebuild the project. I haven't been able to trap where it's happening using breakpoints.

It's happened a couple times in the last few days. What should I be looking at to fix this?

Thank you!

Answer 1

Have you tried to enable Fusion Logger to see if it's an assembly that is failing to load? In C# you can tell the debugger to break at any exception (There's a command you can add by customizing the tool bar called Exceptions). I'm not sure if VB has this but I would assume they do. Can you tell it break on FileLoadException and that might help you understand what's going on.

The line of code you added is pretty innocuous. When you add the code it breaks, have you then done a clean build with that line of code still in and does it work or not?

Answer 2

I did run the Fusion Logger, but did not get any results when the exception occurred. I tried all 4 settings.

The new line of code runs fine after a clean/rebuild.

I haven't used the break on all exceptions before; I'll see if I can find it.