When a user follows a link to a survey (for example, by clicking the link in an email) and the instance has SSO authentication enabled, after authenticating, they are redirected to a null page, Page Not Found
The URL might be something like <instanceName>.service-now.com/nav_to.do?uri=%2Fnull
When SSO authentication is enabled, if the assessment_take2 page is a public page, the link to the survey won't work.
Make the assessment_take2 page a non-public page:
1. In the Application Navigator, enter sys_public.list
2. Filter the Page column for starts with assessment.
3. You should see 2 matching records, one for assessment_take2 and another for assessment_thanks.
4. Modify the Active value for the assessment_take2 public page to false.
5. Leave the Active value true for the assessment_thanks public page.