When connecting to a managed system, often times there may be errors. For example, security may be preventing access or certificates may be incorrectly configured. This will return error codes which the agent or connection manager will record in the logs. However, rather than look at the logs, you can see these errors in several places.
First, in the Management GUI, for the specific Manager under properties, you will find Last Error Code. In this example, the error is a 2059 from an IBM MQ Queue Manager indicating it is not available.
Administrators can also see this error published as a metric under the manager in the Enterprise Manager. In this case, the REASONCODE reflects the same 2059 as above and since it is not available, the other metrics are not reported.