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PME 7.2.x/8.x: Web Applications HTTP error 500.19 - This configuration section cannot be used at this path.


Opening the PME web application in a web browser yields the following error.

Configuration error reads:
This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault="Deny"), or set explicitly by a location tag with overrideMode="Deny" or the legacy allowOverride="false".

Other notes:
  • All other parts of the PME system are functioning as normal - devices are connected in Management Console, and Vista is displaying real-time values.
  • Web application may have been working previously.
  • User may have re-installed Windows OS or IIS.


  • PME 7.2.x/8.x Web Application
  • Windows OS
  • IIS or OS may have been reinstalled


One of the Application Development features is not enabled.
This can happen when IIS or the operating system is re-installed or updated.


If using Windows 7 or 8, open the Start menu and type "Turn Windows features on or off" into the search bar.
In the features window, open Internet Information Services > World Wide Web Services > Application Development Features
Enable all features and close the window.

If using Windows Server 2012, open Server Manager, then click Manage > Add roles and features.
Click next, then select the PME Server in the Server Selection window and click Next.
In the Server Roles window, expand Web Server (IIS) > Web Server > Application Development.
Ensure that the latest .NET and ASP.NET features are selected, as well as CGI, ISAPI Extensions and Filters, and Server Side Includes are selected.

The following command may unlock that part of the file for all virtual roots:

(Generic command): Do not run command as-is, make changes where necessary.

The following command will unlock this section globally.

%windir%\system32\inetsrv\appcmd.exe unlock config -section:system.webServer/security/requestFiltering

If you only want unlock it for a particular site/app, you can do

%windir%\system32\inetsrv\appcmd.exe unlock config "SiteName/app/url" -section:system.webServer/security/requestFiltering

For System DataService:
%windir%\system32\inetsrv\appcmd unlock config -section:system.webServer/modules


After doing the procedure outlined in this KB, the Web Application may return a new error - HTTP Error 500.21.
If this occurs, see KB FA271594.
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