Jul022014

Resolve an HTTP Error 500.21 in IIS

If you've setup a new IIS website and app pool and try hosing a .NET application, you may run into this error: HTTP Error 500.21 - Internal Server Error Handler "ExtensionlessUrlHandler-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list.

HTTP Error 500.21 - Internal Server Error Handler ExtensionlessUrlHandler-Integrated-4.0 has a bad module ManagedPipelineHandler in its module list

Luckily, it's very easy to resolve. Run the follow command from an elevated command prompt:

%windir%\\Microsoft.NET\\Framework64\\v4.0.30319\\aspnet\_regiis.exe -i

If you're on a 32-bit machine, you may have to use the following:

%windir%\\Microsoft.NET\\Framework\\v4.0.30319\\aspnet\_regiis.exe -i

Reinstall ASP.NET in IIS

Try reloading your site; you should be set to go!