MDM Certificate about to expire, and unable to renew it.

Use Server.app to renew the certificate. If you are on Mojave Server (5.8), then select Profile Manager and under the Settings section click the Configure button. The sheet will contain a Renew button. Start the renew from that location.

On older versions of Server, select your server from the top of the list > choose the Settings tab > click the Edit Apple ID... button in the Notifications section. On that sheet, press Renew... and follow the prompts.

Make sure you are using the same Apple ID to renew. Only 3rd Party certs can be renewed from the cert management page, not macOS Server certs.

Hope this helps.

Reid

Silly suggestion... If you double click the certificate to inspect it, does it have a Renew button on the bottom of the sheet?

Which services are enabled on your Profile Manager? ABM, DEP, VPP?

If you created the CSR but have not yet purchased a certificate, that would explain why your cert is in pending state. If you are going to protect the server with a public cert (good plan), then the process is (1) to define a host name (like mdm.yourdomain.com), (2) generate your CSR and private key (created when you get the CSR), and then (3) upload the CRS to your certificate provider. They will then generate your public key. (4) Once you have the public key you add it to your pending certificate and you complete the public/private key pair. This will allow you to host the service using public key infrastructure and not have to worry about manually trusting self-signed certificates.

Hope that is clear. Certificates can be confusing if it is your first time working with them.

Reid