Asp.net failed to start in dot net 4.0

Question

The website was developed in dot net 3.5 SP1 and works fine in dot net 3.5 SP1. But, having recompiled it to dot net 4.0 and changing the application pool to "integrated", he could not start. The symptom is that the website is working fine for several minutes. Then the following message will appear:

[NullReferenceException: the object link is not set to the instance object.]
System.Web.PipelineStepManager.ResumeSteps (Exception error) +197
System.Web.HttpApplication.BeginProcessRequestNotification (HttpContext context, AsyncCallback cb) +89
System.Web.HPpRuntime (IIS7WorkerRequest wr, HttpContext context) +189

If we recycle the application pool, it will work for several minutes, and then the same error will appear.

Any help is appreciated.

Lau.

Answer 1

In the call stack, I think this exception was caused by a problematic HTTP module or handler.

You should be able to debug using Visual Studio or WinDbg.