The Deployment Result "Downgrade not supported" is displayed on Deployment tab when attempting to upgrade a Change Auditor Agent to version 6.9.
A log line similar to the following is recorded in the Change Auditor Coordinator log file:
2017-01-01 18:07:04.543 [ERROR][ChangeAuditor.Sys.RemoteDeployment.ThreadProc(0)] Error deploying to DC1.testdomain.com: Agent host already has a newer agent version deployed. Downgrade not supported.; Operating System: Windows 2008 (32-bit) SP 2; .Net Versions: 2.0.0 SP 2, 4.0.0, 4.5.0, 4.5.1, 4.5.2
The version of Change Auditor 6.8 that is packaged with Change Auditor 18.104.22.1685 is 22.214.171.1245.