Question

When running IIS, I’m getting the below error on all ASPX pages. ASP.NET is registered for versions 2.0 (with 3.5 extension) and 4.0. I’m running 2.0. Is there some setting I’m missing? I’m not sure what information is needed to better facilitate some help, so let me know what you need and I’ll post it up as an edit.

Server Error in ‘/’ Application.

Object reference not set to an instance of an object.
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.

ERROR MESSAGE

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

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 identified using the exception stack trace below.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
System.Web.Hosting.ISAPIWorkerRequestInProc.GetServerVariable(String name) +784
System.Web.Security.WindowsAuthenticationModule.OnEnter(Object source, EventArgs eventArgs) +117
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

Answer 1

Normally a NullReferenceException is fairly easy to debug in code by debugging, but that stack trace appears to begin in framework code, so it’s not your code that’s failing.

In all likelihood, there’s a problem with the .NET installation on IIS. (The fact that it starts in ISAPIWorkerRequestInProc is the biggest clue, I think. That’s where the code interacts with the worker process.) Try running:

aspnet_regiis.exe -i

(info here) to re-install the IIS components of the framework.