SUMMARY
Boomerang mis-recognizes the guest OS of VMs and I cannot select those VMs
ISSUE
Boomerang relies on the guest OS settings to recognize the guest OS running in each VM. If Boomerang does not allow for selecting VMs on creating a Protection Group even when the actual guest OS is in the list of supported OSes, please check the guest OS set in VMware is correctly set.
You can make changes to Guest OS Version from vSphere Client if you are certain the Operating System in your VM is compatible.