Comment 3 for bug 1872436

Meanwhile I found out that to enable the FP reader in Kubuntu you have to add these lines to the common-auth file in pam.d folder:

# here are the per-package modules (the "Primary" block)
auth [success=1 default=ignore] pam_unix.so nullok_secure
auth [success=2 default=ignore] pam_fprintd.so max_tries=1 timeout=10
auth [success=1 default=ignore] pam_unix.so nullok_secure

With this it works, but one problem still exists. After a reboot the first login fails very often, you have to repead the login. Sometimes it works sometime not.
When you logged in once, and lock the computer then the unlocking with FP reader works fine. Also in oher situations.