I prepared a bootable USB device - a Lexar 8Gb SDHC card that I have been using in my dual boot Linux box (LibreELEC/Kodi or Linux Mint) for several months - according to the simple and clear x86 instructions here at the Volumio website. However, Volumio will not finish booting. (Linux Mint still boots fine from the internal SSD.) The USB keyboard works during initial boot, but not after the aborted Volumio load attempt.
Here is a pic of the error:
And the partitions on the SD Card: