Issue
When using SSO with ADFS, and adding a certificate that expires at a certain date, you notice that logging in becomes impossible two weeks before the expiration date.
Resolution
It is because the certificate is changed on the IDP 2 weeks before expiration date. Even though ServiceNow polls the IDP for a new certificate it actually happens starting from the expiration date.
To solve it, you need to take the certificate of the IDP and set it on the ServiceNow instance, replacing the old one.
