I tried to implement a custom web authentication error page on application level based on these guidelines: link.
Unfortunately, the custom $$ReturnAuthorizationFailure form never appears when accessing a document I did not have access to. Instead the default error page is being displayed.
I found a discussion on the ND 4/5 forum:
Is it possible to use custom forms when using session based authentication? (link)
One answer says Yes, the other says No. Which one is correct?