Symptom:
Digital networking replication service does not start.

Having following exception in Replicator log:
===========================
13:31:37.681 HDR|03/17/2014 ,Significant
13:31:37.681 |4463,,,CuReplicator,0,Digital Networking is not enabled. Unrecoverable exception, excp: java.lang.NoClassDefFoundError: com/cisco/unity/networking/ObjectFactory
13:31:37.682 |4463,,,CuReplicator,0,com.cisco.unity.networking.ReplicatorLogger!! Call Stack Trace of the Exception (reverse order)!!
13:31:37.682 |4463,,,CuReplicator,0,com.cisco.unity.networking.ReplicatorLogger0 : com.cisco.unity.networking.Replicator.main(Replicator.java:592)
13:31:37.682 |4463,,,CuReplicator,0,com.cisco.unity.networking.ReplicatorLogger1 : com.cisco.unity.networking.Configuration.isNetworkingEnabled(Configuration.java:349)
13:31:37.682 |4463,,,CuReplicator,0,com.cisco.unity.networking.ReplicatorLogger2 : com.cisco.unity.networking.database.Directory.<clinit>(Directory.java:74)
=====================

Conditions:
Running CUC 8.6(2)SU4