Fixing HTTP Error 500.21 – Internal Server Error Handler “WebServiceHandlerFactory-Integrated” has a bad module “ManagedPipelineHandler” in its module list on IIS.

I was recently developing some .net web applications at work and finally took the plunge of setting up a server to host them after I was happy that we had reached the point where they were usable applications.  So after setting up Server 2008 R2, I went ahead and enabled IIS with configuration enabled along with a host of other modules enabled to support what we were after. Gave the server a reboot and everything was up and ready to go.

Moved over to my development machine and instructed Visual Studio to publish an application to this newly setup web server, everything up until this point had worked perfectly, the web app published without any errors. So I opened up Internet explorer and low and behold error, page cannot be displayed. So I’m like maybe it’s a permissions thing, remoted into the web server and viewed it as a localhost and got Error 500.21 – Internal Server Error  Handler “WebServiceHandlerFactory-Integrated” has a bad module “ManagedPipelineHandler”.  I had gone ahead and configured an application pool for the web apps we were going to use, and everything seemed OK.  I then remembered something, in the good old IIS 6 days you had to run a .net registration program to notify IIS you had it installed and register the handlers for .net, but thinking to myself this is now 2008 R2, come on, it couldn’t be that.

I opened up an elevated command prompt window and navigated to C:\Windows\Microsoft.NET\Framework\v4.0.30319 and ran aspnet_regiis.exe -i causing to register itself with IIS and enable the handlers required to run .net pages.

After running this command I rebooted IIS and bang the web application started working.  An easy fix but a pity that it couldn’t have run automatically when I insist on installing under the IIS configuration.


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