As part of standard IT security good practice for web applications we update the certificates of the platform on an annual basis. The old certificate is valid until 27 December 2022, and the new certificate will be valid through 29 December 2023.
For customers accessing the platform via single sign-on, this means that you also need to update certificates in your identity provider.
This is a standard process done on a routine basis by IT organisations.
Your AD (or other Identity Provider) administrator needs to add our metadata to AD, per usual process for SSO applications
Platform metadata is available at https://PLATFORMNAME.platform.co.nl/saml2/metadata/
where 'PLATFORMNAME' is the name of your specific platform.