The domain cannot be accessed with Server Error 500.19 – Internal server error. There is a problem with the resource you are looking for, and it cannot be displayed.

Symptoms

• The website displays the following error:

  Server Error 500.19 - external server error. There is a problem with the resource you are looking for, and it cannot be displayed.

• Enabled Failed request tracing for example.com shows:

  Error: websrvmng failed: Filename: ?C:Inetpubvhostsexample.comhttpdocsweb.config
  Line number: 15
  Error: There is a duplicate 'system.web.extensions/scripting/scriptResourceHandler' section defined

Cause

The application/website requires a specific version of the framework (ASP.NET 3.5) that is not compatible.

Resolution

Install the required ASP.NET version (ASP.NET 3.5) by following this article: How to enable ASP.NET 3.5 / ASP.NET 4.7 in Plesk for Windows Server