PCO V12.0 only has Application Manager as an option for eventbases instead of Operations Manager and Applications Manager. Why is the OM eventbase missing?
Operations Manager was discontinued after 11.2 and was replaced by the Event Engine starting v12.1. Policy Orchestrator v12.0 is a standalone event processing product. The analytics / dashboarding capability that were introduced in v12 replaced the pre-existing capability that were handled in Policy Orchestrator.
Workaround: Customers could try using PCO from v11.2 in v12 if needed. However, please note that PCO from 11.2 against v12 was not tested and is not supported. Even if it works, there’s no guarantee that it wont break with version v12.1 and v12.2. In v12.1 the Event Engine was introduced to replace the PCO event processing capabilities.