I haven't tried using flasher3.12 since it says that version is for Harmatten, so I just assumed it won't work and I assume that is the source of your error. Try the 32-bit flasher-3.5 use the tar.gz so you don't need to force the installation, I doubt it will work since it doesn't even run on my 64bit Arch Linux box, but Ubuntu might be different. If it doesn't work, I guess you need to boot from a 32-bit live CD/USB to run it.