Just my 2 cents here, I've tried the VHD before but can't remember if it worked or not.
I think it didn't, hence I always did manual installs.
These days I use HardenedBSD because it has mitigation build in, and there is no VHD file available.
Other then that, FreeBSD works great. OPNsense (running on top of FreeBSD) works perfectly.
Gen1 and Gen2, btw.
Also, what manxam says. "will not boot" is very vague.