I recently worked with one of my customer who was getting “HTTP 500.19” error while browsing the website.
Server Error in Application "application name"
HTTP Error 500.19 – Internal Server Error
Description of HRESULT
The requested page cannot be accessed because the related configuration data for the page is invalid.
Err tool showed “STIERR_INVALID_HW_TYPE” for 0x8007000d error code.
With further troubleshooting found that he had a virtual directory configured for a UNC share, and had a wrong password mentioned. Entered the proper credentials, and the problem went away.
This error message is a generic error message which would occur when the site configuration data present in the applicationHost.config has a malformed entry, or not a valid data (in our case it was the wrong password for the UNC connection, and the IIS cannot read its web.config file to check if there is any system.webserver setting mentioned)
Related KB : http://support.microsoft.com/kb/942055