In general, The HTTP Error 500 is a "server-side" error, meaning that the problem is not with your PC or your Internet connection. Instead it is a problem with the web site's server. With Wonderware Information Server this could mean that something is wrong in COM+ settings, the verification of SuiteVoyager Database connection, license verification, etc.
Error http 500.19 may appear when reinstallation of WIS is executed. Later, when the application is restored and the configuration looks well, when WIS portal is loaded the administration panel under System panel is not visible, and the error description on the web page that displays when you try to click on Active Factory Reports or one of the Historian Client tools such as Query :
HTTP 50.19 may be due to a number of issues involving the web.config file which can be found on one of several locations under:
It is possible that either the page is attempting to add or configure something called an Internet Server Application Programming Interface or ISAPI.
The Internet Server Application Programming Interface (ISAPI) is an N-tier API of Internet Information Services (IIS), Microsoft's collection of Windows-based web server services. It is made up of a number of configurable "sub-applications" for which extensions and filters can be applied.
If you are experiencing this issue, you will see the HTTP Error 500.19 - Internal Server Error with one of several possible Wonderware logger messages. If the error is accompanied by the following error in the SMC Logger:
Cannot add duplicate collection entry of type add with unique key attribute name set to xoml-ISAPI-2.0 Config File c:\inetpub\wwwroot\Wonderwware\web.config
To resolve this issue, edit the web.config file (using Notepad) located at C:\inetpub\wwwroot\Wonderware\ and delete the two ISAPI lines you see under <handlers accessPolicy="Read, Script">.
Save your changes and close the editor.
If you are experiencing HTTP Error 500.19 - Internal Server Error, accompanied by the following or similar error in the SMC Logger:
Unable to set property AccessFlags for application /AFWeb SetProperty exception:
Line number: 83
Error: Cannot add duplicate collection entry of type 'add' with unique attribute 'name' set to 'PageHandlerFactory-ISAPI-4.0_64bit'
Open Windows Explorer and navigate to:
Open Web.config in Notepad, and look for <handlers accessPolicy="Read, Script">
For each <add name="...-ISAPI..." /> you will need to add a corresponding line <remove name=...-ISAPI..." />
Note that you should add the <remove name...> lines before the <add name...> lines, although the order is not important so long as there is a corresponding <remove name..> for each <add name..>
Save and reboot