After upgrading from PS 11.4 to PS 11.5.1, the PacketShaper S-Series appliances cannot connect to IntelligenceCenter 3.3.3.
PS 11.5.1 includes the secure cipher suite for TLS, causing connectivity problems with IC 3.3.3 which doesn't support these stronger ciphers. Previous 11.x versions do not have the stronger ciphers, so it isn't an issue.
Set PacketShaper to a weaker cipher strength and reset the appliance:
# sys set useStrongCiphers 0