This exact same question was asked here but the community missread and marked inacurately as a duplicate.
I am also NOT asking HOW TO install. I am asking asking the same as the user!
ubuntu 16.04 fingerprint-gui was working great just 1 hour ago.
I've upgraded to a fresh clean install of ubuntu 18.04 followed the link below to install fingerprint gui but i can confirm that the same behavour the user above is facing i too am facing. all of my /etc/pam files have referenced gdm authentication and not lightdm as used before. i can use the fingerprint scanner with any terminal sudo//su command. However it does not work for pam authentication or gdm. Has anyone found a solution yet?