You create a user exception page in policy and successfully apply in a Web Access Rule in VPM.
The exception gets hit in policy and calls the exception page successfully.
If you now go to Configuration >>> Policy >>> Exceptions >>> View File: Exceptions Configuration you get a page listing all of the User-defined and built in Exceptions.
Find and click on your user defined exception “View Sample HTML” and you get the following message:
No exception found called 'user-defined.custom_deny'
If the user exception is working correctly then we must be looking at a syntax issue on the viewer.
The problem is related to the exception name you have used, do not prefix the exception page name "
So in the example, instead of "user-defined.custom_deny" change it to "custom_deny" and apply the change.
The “View Sample HTLP” page prefixes the exception page with the “user-defined” tag.