If you were using pfSense on a bare-metal device, you wouldn't see any issues.
@bahman said in error occur under startup:
qemu
So this concerns "VM" or "Virtualisation" => see here Home > pfSense® Software > Virtualization
as this is not an installation problem, pfSEnse or the software that boots / installs pfSense doesn't get even the chance to start.
The messages shown are from the VM host.
I tend to say : a qemu problem.