Manually reorder the cipher suites on the SQL Server with a Windows Group Policy. For detailed steps, see this Microsoft document.

Install or update the certificate used by the SQL Server or other registered server. For more information about how to use a secured connection to the SQL Server, see KB84628 - Configurations for ePolicy Orchestrator certificate validation issue for secure database connection.

NOTE: Other registered server types might also be affected if they use SSL.

Example:
You have a registered LDAP server and you use the secure connection. The connection fails if the certificate provided by the LDAP server uses an RSA 1024-bit public key.
The solution in this scenario is to update the certificate on the LDAP server to not use a 1024-bit RSA public key. 

ePO 5.10.0 and later
ePO has migrated away from the RSABSAFE library in favor of Bouncy Castle. This issue is far less likely to occur in the Bouncy Castle library. But, it can occur if the cipher suite on the SQL Server is severely restricted.

The epo.java.security file, located in <ePOInstallDir>\Server\Conf\Orion, defines the list of ciphers that ePO can consume when acting as a client. In this scenario, ePO is the client and Microsoft SQL is the server.

Below is the list of ciphers present in the epo.java.security file in the base install package of ePO 5.10.0:
NOTE: An upgrade is successful as long as the cipher suite on your SQL Server contains a minimum of one of the above ciphers, regardless of the order.