Could be broken ISO downloaded or on the host. I have got same error 08-19-2015 FreeBSD 10.2 disc1 64bit, disc1 386 and even DVD
3 badly downloaded iso's would be rather odd? I think the problem is dev-side/host-side. Tried to load 10.2 on 3 differen machines(usb cdrom and ata cdrom) also on virtualbox(ata). On machine with usb cdrom it ends up with this error 19 on ata turns off the pc power 1 second after mount attempt. On Virtualbox crashes it. https://forums.freebsd.org/threads/52791/
I had succesfully installed FreeBSD 11 30-12-2015 on virtualbox. It's even simpler and faster install than PCBSD(TruOS).