Cloning and/or moving vMA is not supported by VMware, this has been the case since VIMA 1.0. If you take look at the "Known Issues" in the vMA release notes, you will see there is no still workaround. Users may find it useful to be able to clone vMA for backup purposes or to deploy another vMA without having to re-download or re-uploading .OVF from your local desktop/VMware's website.
I suspect that VMware may have allowed cloning of vMA, but just did not update their release notes? The only thing you have to do is manually fix the UUID if you do not want to see the warning message. If you would like to fix this for VIMA 1.0, you will need to do the same thing except you need to modify the UUID found in /etc/vmware/viconfig/viconfig.xml and restart vMA for the changes to effect.