After ICS POD upgraded to 18.2.3.0.0, ICS agent will not
come up and throw an error "Agent Group Existence Check Failed,
Recheck ICS Username, ICS Password and Proxy Username, Proxy
Password or Contact Customer Support".
The reason being of the issue is, ICS certificate has been changed.
Certificate changes for ICS happened on the Cloud (outside of
Agent). It can be mapped to 18.2.3 MLR 00.
This is known Bug 28242477 logged by Oracle.
To resolve this issue, the user needs to...