As a matter of fact I did that last time the problem occurred. The only warning I couldn't understand is: kioslave5[15897]: kf.kio.slaves.http: MD5 checksum MISMATCH! Expected: "<something>==" , Got: "<something>" I can't even see failed login attempts, the last entry mentioning pam_unix shows the subsequent console login. From what I can tell, sddm uses sd-pam for authentication, perhaps I need to enable systemd debug logging?