Njanyana,
I finally got some time to play with NGS3, and solved your problem with EXOS v15.7.1...
The console was showing a
Warning. Could not determine the CPU Familymessage.
So, after some investigation on the start options for QEMU, I found that all that it takes is to add
-cpu core2duoin Advanced Settings - > Options.
With that change the VM will boot without problems...