classic application pool not working in the debugger

I have upgraded my website to framework 4.5.2 I want to use a classic application pool as it was before the upgrade.

When I try to run it by pressing F5 I get an error

HTTP Error 500.22 - Internal Server Error
An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.

Most likely causes:
This application defines configuration in the system.web/httpModules section.

Things you can try:
Migrate the configuration to the system.webServer/modules section. You can do so manually or by using AppCmd from the command line. For example, from the IIS Express install directory, run appcmd migrate config “Default Web Site/”. Using AppCmd to migrate your application will enable it to work in Integrated mode. It will continue to work in Classic mode and on previous versions of IIS.
If you are certain that it is OK to ignore this error, it can be disabled by setting system.webServer/validation@validateIntegratedModeConfiguration to false.
Alternatively, switch the application to a Classic mode application pool. For example, from the IIS Express install directory, run appcmd set app “Default Web Site/” /applicationPool:“Clr4ClassicAppPool”. Only do this if you are unable to migrate your application.

Detailed Error Information:
Module  ConfigurationValidationModule
Notification    BeginRequest
Handler ExtensionlessUrl-Integrated-4.0
Error Code  0x80070032
Requested URL   http://localhost:64182/
etc

The default website is already classic and I want to get the website working as classic.

I had the website project set to integrated for some reason. To fix it, I went to properties and set it to classic.