Wait... after upgrading to v 10.***... can you downgrade to 2.0.4***? it that is possible imma try it now
Yes, you can downgrade from the BB10 builds to any of the PB OS versions containing fingerprint.dat I believe. (i.e. 2.0.0.7111 and above or something like that). You can definitely downgrade to 2.1.0.385, but I'm fairly sure you can go to any of those others as well.