Mounting failed with error 19 during installation

[shelter]

I'm trying to install OPNsense (for the first time) on my Qotom box using USB. But no luck. This is the error I'm getting during the initial startup:

mountroot: waiting for device /dev/ufs/OPNsense_Install...
Mounting from ufs:/dev/ufs/OPNsense_Install failed with error 19.

etc. etc.

Picture of the output on my display: https://tweakers.net/ext/f/Q9fh5nRGpbz0naAnO4ZJM3Zg/full.jpg

Anything I can do to resolve this issue?

[shelter]

Managed to resolve this after two very frustrating nights. I think it was an issue related to an old MBR or broken GPT configuration.

Steps to resolve:

1. Connect an USB flash drive (to my Mac)
2. diskutil list (check who's who)
3. diskutil umount disk2s1 (unmount the flash drive - in my case disk2s1)
4. gzcat pfSense-CE-memstick-2.4.4-RELEASE-amd64.img.gz | sudo dd of=/dev/rdisk2 bs=1m (deploy the image)
5. Install pfSense on the Qotom box using the USB flash drive

Success. The hard disk drive is now OK and ready for OPNsense. Continuing:

6. Connect the USB drive to the Mac once again
7. diskutil list
8. diskutil umount disk2s1
9. sudo dd bs=1m if=OPNsense-18.7-OpenSSL-vga-amd64.img of=/dev/rdisk2

Et voilà.. I am now installing OPNsense!