aspx Errors

Problem

If the following errors are encountered in the Web Client:

• HTTP Error 500.21 - Internal Server Error
• Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list
• The .NET 4.0 handlers may be missing
• To manually add the missing handlers

Solution

Execute 'aspnet_regiis.exe -i' in %WinDir%\Microsoft.NET\Framework\v4.0.30319. If the handlers are still missing, try using the option 'Revert to Inherited' seen on the right-side Actions panel while viewing the handler mappings.