Security Center systems that are backward-compatible with older versions that do not support the Transport Layer Security (TLS) protocol (5.4 and earlier) are more vulnerable to network attacks.
Mobile Server 4.0 does not support Transport Layer Security (TLS) protocol. If you
disable backward compatibility, the Mobile apps and the Web Clients 4.0 can no longer connect
to Security Center. Expansion servers that have not been upgraded to version 5.5 or later also
stop working. Both Web Client 4.1 and the role-based Web Client 5.6 and later support
TLS.