Great, thank you very much. I should've thought of searching for my error
message.
After entering your error message into a search engine, I found several
people reporting the same problem with Ubuntu 18.04, which is the version
Trisquel 9 is based on, if I remember correctly. In the cases I found, a
critical component (libblockdev-crypto2) was missing because it did not ge
Using the 2020-03-29 ISO of Trisquel 9 on a live USB, Trisquel says:
Unable to mount [device]
Error unlocking /dev/sdb[number]: The function 'bd_crypto_luks_open_blob'
called, but not implemented!
It works perfectly fine from an installed Trisquel 7. How can I make it work
from the Trisquel 9
