Symptoms:
The following error may be presented to the user when performing a Failover Test:

Protection group failover test. Completed successfully: failed to ExecuteVmToolsOperations from CreateRecoveryVMsAndViewRecoverBeforeCommit: task id: urn:vcloud:task:dcd0671e-27ce-4a64-8473-76e6833c8af0 with operation vappUpdateVm on https://drsite.acmeinc.com/api/vApp/vm-88db4b92-3c18-42ac-93cc-1f7e33b8d5dc is error , due to : [ 055f3ef9-cff1-4ee4-94ff-69fe10c6b861 ] The operation could not be performed because the argument is invalid. A specified parameter was not correct: spec.memoryAllocation.reservation.

The user may also experience NICs not being attached to VMs upon recovery.  The user may also experience NICs not having the IPs assigned per their VPG configurations.

Cause:
Zerto doesn't support memory reservation for recovered VMs.  The error above prevents VMWare Tools from processing any further operations (such as IP configurations).

Solution:

Uncheck the checkbox (reserve all guest memory) on the source virtual machines.   This can be done in the vSphere Web UI.  Right click the VM > Edit Settings.  Once here, expand the CPU and Memory fields to see what the current reservations are.  Below is an example screenshot of a VM with no CPU or Memory reservations (0 indicates no reservation):

Memory Reservations

The following VMWare KB Article discusses this error in further detail:  Powering on a virtual machine fails with the error: memoryAllocation.reservation