This article explains how to enable the missing Microsoft Internet Information Server (IIS) components generating the 500.21 error when attempting to launch GSX Analyzer for the first time.
The IIS installation wizard does not include all features required by GSX Analyzer during default install, so they must be manually added by selecting them during a custom installation from the Application Development Features in the IIS options.
- HTTP internal Server Error in Browser.
- HTTP Error 500.21 - Internal Server Error.
- Handler "ExtensionlessUrlHandler-ISAPI-4.0_64bit" has a bad module "IsapiModule" in its module list.
- Starting with version 10.5+, the GSX installer runs a prerequisite check highlighting missing IIS components.
The HTTP error message applies to all browsers, it is not browser specific as it is being generated by the IIS as a server error and passed through to the client:
- An HTTP internal server error occurs when something unexpected happens during the execution of a script or compilation at the server level.
- There is nothing that can be done at the client level to fix this.
How to Solve the Issue
The HTTP 500.21 error is caused by a partial installation of IIS, specifically missing ISAPI modules. To fix the issue, we simply need to locate the IIS components and add these missing modules. A simple click to install the components and restart of the IIS server to load the changes will fix the problem.
Microsoft provides a procedure to install the IIS components for each Operating System: Install and Configure Internet Information Services for Dynamics NAV Web Client.
In case you are running Windows Server 2012 and you need to enable ISAPI modules, we also provide a dedicated article on how to install these missing components.