When we
where working on .net mvc or aspx we where configuring into the
web.config file as default error page, like below.
<system.web>
<customErrors mode="On">
<error statusCode="404"
redirect="/PageNotFound?" />
<error statusCode="302"
redirect="/unauthorised" />
</customErrors>
</system.web>
But in .Net
core we dont have web.config file to configure default error page.
In this
case we need to configure it in startup.cs file.
