Zerto Virtual Replication has the ability to issue alerts through vCenter's Alarms feature. The actions triggered by these alarms can be customized by the administrator. When upgrading from one version of Zerto Virtual Replication, an administrator may notice that these customization have been reset.
All versions up to 2.0 Update 1 (Viper)
This is expected behavior for all versions up to 2.0 Update 1 (Viper). The alarms are being recreated, and so the actions relating to these alarms are reset. Starting with Zerto Virtual Replication 2.0 Update 2 (Wolf), alarm actions will be exported prior to upgrade, then reapplied during the upgrade, so as to avoid this issue.