When customer tried to use "Update Service Manager Link" in AWI for one of his agent, they got this error message:
Release: 12.x
Component: Automation Engine
Customer didn't in put the right parameters for Agent to start/stop on AWI. The fact that they are not using the default port 8871 for service manager.
Additionally, it could also be due to the fact that the port 8871 was not opened on the Server hosting the Server Manager towards the AE servers.
The issue is solved after putting in the right information in your agent.