Some applications require VPN or special group permissions to access. Instead of throwing up default browser "Network Unreachable" error message, or default ISV 403 error message, this Enhancement Request is to provide a custom field to put in an error page to make it more friendly to the end user.

For instance, if VPN is required to access the application, display a message to the user to indicate VPN required and click OK to continue.

If a user attribute is required, the only actions allowed are "Block or MFA". It would be nice to have a third option such as "Custom Error Message".