WA System Agent has below errors in the receiver and transmitter logs.
XX/XX/2021 00:00:12.345 PDT-0700 1 TCP/IP Controller Plugin.Receiver pool thread <Regular:1>.CybReceiverChannel.receive[:234] - cybermation.library.communications.CybConversationException: Invalid identifier
The issue occurs in WA DE (CA DSeries) version is 12.3 and agent is on 11.3 release.
Release : CA WADE 12.3
Set the agent Release in Topology to 11.5.
If the agent continues to show Inactive, then delete and add the agent again in Topology.
Note: For R12 agent, set it 11.4 or above.