Your SSL certificates have expired or are close to expiring for some domains. However, when you try to upload an SSL certificate for the Certificate Signing Request (CSR) generated through the Control Panel for your organization, there is the following error: One or more certificates (end-entity, intermediate or root) are missing from the zip bundle. Please obtain a valid certificate chain from CA and upload it again. There is no need to regenerate CSR.
Without the complete trusted certificates chain, you cannot renew SSL certificates. Ask the Certificate Authority (CA) to provide the zip bundle that contains all the certificates, and you will be able to upload the certificates using the Control Panel. However, if this is urgent (time, deliveries, and campaign send-outs are being impacted) do the following to retrieve the missing intermediate certificate from the main certificate:
The SSL certificates should then have been installed for the domains. If the above steps have not worked, connect with the CA.