Serving 404s instead of errors - solved :)
Below comes from email that my customer send to me.
I’ve created a special MVC Route Handler that simply serves a 404 error.
In the Global.asax, we can now add what we would like to serve a 404.
Like so

This will stop the errors being sent to us, while providing the user with the correct response for missing items.
The route handler simply goes

浙公网安备 33010602011771号