When attempting to import a Wildcard certificate for the MDM server in "Manage MDM certificates", an error appears:
"Failed to import server certificate, The certificate with thumbprint/thumbprint <cert thumbprint> already exists"
ITMS 8.6 RU2 and later with SMP using SSL/HTTPs
This has been seen when attempting to import a Wildcard Certificate for MDM that was also being used for SSL connections on the SMP.
MDM requires a different certificate to be used/Imported than what is currently bound on the SMP or site servers for SSL/HTTPS agent connections.
MDM requires certificates that are not already in use by the SMP or Site Servers. This issue may only be seen if using Wildcard certificates since they can be issued to multiple devices within the domain.
Additional requirements for the MDM server certificates can be found in Broadcom's documentation: Server Certificate for the MDM Server