The marketplace provides CAU RA agent and Java Agents (like SAP, SQL, or Peoplesoft agents), but the upgrade cannot go through.
When attempting to upgrade, the screen shows a "Target Version" of " Manual Upgrade Required ":
Can the Centralized Agent Upgrade on a 12.3.x system upgrade Java based agents that are 21.1 or 12.2?
Release : 12.3
Component : AUTOMATION ENGINE
12.1 and 12.2 Java-based agents cannot be upgraded via CAU. The first available version to update the Java agents via CAU is a 12.3.0 agent or above.
The documentation will be enhanced to state that when "Target Version" shows as "Manual Upgrade Required" it means that the agent does not meet one of the requirements (is to old version, etc...)
Make sure that Service Manager is also on version 12.3.0 or above.
More information can be found in the documentation for CAU:
"Java agents: CAU is available for Java agents as of v12.3. They must be started by a Service Manager of v12.3 or later in order to be upgradeable via CAU."