Microsoft Licensing Briefs: Virtualization
After the re-location of a VM from one physical host to another, the Microsoft Licensing mechanism sees that the the server hardware has changed and requires the Windows license to be re-activated. Please note that is a general issue not specifically limited to Zerto because while Zerto is hardware agnostic, the Windows operating system is not hardware agnostic by design.
It is possible to create a script to automate the license activation upon recovery if needed. For more information on running scripts before or after recovery of a VM, please review the section "Running Scripts Before or After Recovering a VPG" within the "Zerto Administration Guide" provided below.
Note: If additional clarification on why specific VMs require license re-activation, it may also be advisable to contact Microsoft support.