In earlier version of Aria Operations prior to 8.14, there was a limit of 1000 VM entries viewable from the Environment page.
Aria Operations 8.14 and later
In previous versions of Aria Operations there was a limit of monitoring <=1000 VM's.
Starting with Aria Operations 8.14 and later, application monitoring of > 3000 VMs per vCenter Server is possible.
However, all of the vCenter VM's should be viewable Aria Operations from:
To workaround this issue, navigate to the VMs under Administration > Inventory, or by searching for them by name in the upper right hand corner.