This article describes how to avoid a known issue in certain versions of Neverfail Heartbeat. These versions are known to be prior to 4.6.1
After starting a rollback operation you should not start or stop replication until the rollback is complete. Similarly you should not start or stop any services that affect the application.
When clicking the "Rollback" button, you are presented with a confirmation dialog, this dialog give instructions not to press Start or Shutdown until the completion of the rollback operation.
For further information please contact Neverfail Support.