We have a regular maintenance scheduled for Mon Jan 14th, 2019 - starting at 9.00 AM PST. During this maintenance window, we will be updating Apigee Single Sign-On's SAML SP metadata signing certificate. For more information on how to update your IDPs refer: https://docs.apigee.com/api-platform/system-administration/update-edge-sso-cert
This maintenance is expected to take 2 hours, and is not expected to cause any interruption to Apigee Edge. If you encounter login issues post this maintenance, please reach out to Apigee Support.