The 500.19 is thrown while accessing the Information Centric Tagging (ICT) monitoring console, with an error related to the authentication configuration.
Resolution
Please follow the next steps in order to fix the error:-
In the ICT server, go to C:\inetpub\wwwroot\ICT\monitoring
Open a command line as an Admin
type notepad web.config
Go to line 76 (<authentication mode="Windows"/>) and comment it - <!--authentication mode="Windows"/-->
Save the web.config
Access the Monitoring console to check if it is solved