After installing AppDynamics Database Agent, if you see error messages similar to the following code the issue may be with OS monitoring for your Database collector.
15:33:48,718 ERROR [Agent-Scheduler-1] AServerCollector:199 - Error collecting hardware metrics for server 'kpi'
com.singularity.ee.agent.dbagent.collector.server.connection.ServerConnectionException: org.jinterop.dcom.common.JIException: Message not found for errorCode: 0xC0000001
The message indicates that the WMI permissions were not properly set to collect hardware metrics from the OS. Validate your WMI security permissions as described in the documentation WMI Permissions and Security.