If you’re working in a dev environment and you’ve implemented something like this to your web.config, then you’ll notice some odd behavior relating to survey responses.

If your surveys are set to allow only one response per user, and your web.config CallStack property is set to true, just be aware that you’ll encounter the standard ASP.NET server error:

Server Error in ‘/’ Application error: You are not allowed to respond again to this survey.

It’s just a bit uglier for users to see something like the above instead of the standard SharePoint error page. Just something to watch out for. Regardless, it’s probably  not a good idea to have CallStack set to true in your production environments.