Configuration config = WebConfigurationManager.OpenWebConfiguration("/MyApp");
HttpRuntimeSection hrs = (HttpRuntimeSection) config.GetSection("system.web/httpRuntime");
hrs.EnableHeaderChecking = false;

  builder.Services.AddW3CLogging(logging =>
    logging.LoggingFields = W3CLoggingFields.All;

    ... )

...
  <appSettings>
    <add key="aspnet:UseLegacyEncryption" value="true" />
  </appSettings>
...

<configuration>
  <system.web>
    <authentication>
      <forms protection="All">
	   <credentials passwordFormat="Clear">
   		<user name="user1" password="my_password"/>
		<user name="user2" password="my_password1"/>
        </credentials>
    	 </forms>
    </authentication>
  </system.web>
</configuration>

...
<configuration>
   <system.net>
   <settings>
      <httpWebRequest useUnsafeHeaderParsing="true" />
   </settings>
   </system.net>
</configuration>
...

Page.EnableViewStateMac = false;

<configuration>
  <system.web>
    <authentication>
      <forms protection="All">
	   <credentials passwordFormat="Clear">
   		<user name="user1" password="my_password"/>
		<user name="user2" password="my_password1"/>
        </credentials>
    	 </forms>
    </authentication>
  </system.web>
</configuration>

public ActionResult UpdateWidget(Model model)
{
  // ... controller logic
}