A NWE multiserver environment with secondary servers is having flapping issues with the connectivity of online/offline machines where the machine on a secondary server suddenly goes offline when attempting to start a scan. Hitting refresh in the machines window eventually see's the machine return online.
It is impacted when a secondary server is decommissioned or otherwise changed within the environment.
The cause of this issue is a bug in the MSSQL view job that causes the machine to incorrectly appear offline in both the machines view and the individual machine window.
The permanent resolution to this issue is to upgrade to 220.127.116.11 where the bug fix is incorporated for this issue or upgrade to the 11.3+ version of Netwitness Log Hybrid.
Clearing the cache on the UI or waiting for the machine to return online will show the machine as online again, but will not prevent it from going offline with a scan. Only upgrading to a fix version will prevent this issue.