Why Has My Lock Screen/ Login Screen Turned Black?

5 replies [Last post]
davidpgil
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Joined: 08/26/2015

I don't know what I did. I rebooted and now my login screen is black with a non-blinking cursor in the upper left. Remarkably if I type my password I can still login. How can I restore the normal login screen?

Magic Banana

I am a member!

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Joined: 07/24/2010

Assuming you use the default display manager, LightDM, what does the following command return?
$ journalctl -u lightdm

davidpgil
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Joined: 08/26/2015

davidphilipegil@thinkpadw541:~$ journalctl -u lightdm
-- Logs begin at Sun 2019-05-05 21:46:19 EDT, end at Thu 2019-05-16 07:33:21 EDT
May 05 21:46:24 thinkpadw541 systemd[1]: Starting Light Display Manager...
May 05 21:46:24 thinkpadw541 systemd[1]: Started Light Display Manager.
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM unable to dlopen(pam_kwallet.so)
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM adding faulty module: pam_kwalle
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM unable to dlopen(pam_kwallet5.so
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM adding faulty module: pam_kwalle
May 05 21:46:25 thinkpadw541 lightdm[1101]: pam_unix(lightdm-greeter:session): s
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM unable to dlopen(pam_kwallet.so)
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM adding faulty module: pam_kwalle
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM unable to dlopen(pam_kwallet5.so
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM adding faulty module: pam_kwalle
May 05 21:46:26 thinkpadw541 lightdm[1169]: pam_succeed_if(lightdm:auth): requir
May 05 21:46:41 thinkpadw541 lightdm[1169]: gkr-pam: unable to locate daemon con
May 05 21:46:41 thinkpadw541 lightdm[1169]: pam_unix(lightdm:session): session o
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM unable to dlopen(pam_kwallet.so)
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM adding faulty module: pam_kwalle
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM unable to dlopen(pam_kwallet5.so
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM adding faulty module: pam_kwalle
May 05 21:50:39 thinkpadw541 lightdm[2973]: pam_unix(lightdm-greeter:session): s
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM unable to dlopen(pam_kwallet.so)
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM adding faulty module: pam_kwalle
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM unable to dlopen(pam_kwallet5.so
lines 1-23...skipping...
-- Logs begin at Sun 2019-05-05 21:46:19 EDT, end at Thu 2019-05-16 07:33:21 EDT. --
May 05 21:46:24 thinkpadw541 systemd[1]: Starting Light Display Manager...
May 05 21:46:24 thinkpadw541 systemd[1]: Started Light Display Manager.
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM adding faulty module: pam_kwallet.so
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:46:25 thinkpadw541 lightdm[1101]: PAM adding faulty module: pam_kwallet5.so
May 05 21:46:25 thinkpadw541 lightdm[1101]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM adding faulty module: pam_kwallet.so
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:46:26 thinkpadw541 lightdm[1169]: PAM adding faulty module: pam_kwallet5.so
May 05 21:46:26 thinkpadw541 lightdm[1169]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "davidphilipegil"
May 05 21:46:41 thinkpadw541 lightdm[1169]: gkr-pam: unable to locate daemon control file
May 05 21:46:41 thinkpadw541 lightdm[1169]: pam_unix(lightdm:session): session opened for user davidphilipegil by (uid=0)
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM adding faulty module: pam_kwallet.so
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:50:39 thinkpadw541 lightdm[2973]: PAM adding faulty module: pam_kwallet5.so
May 05 21:50:39 thinkpadw541 lightdm[2973]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM adding faulty module: pam_kwallet.so
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:50:41 thinkpadw541 lightdm[3051]: PAM adding faulty module: pam_kwallet5.so
May 05 21:50:41 thinkpadw541 lightdm[3051]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "davidphilipegil"
May 05 21:51:16 thinkpadw541 systemd[1]: Stopping Light Display Manager...
May 05 21:51:16 thinkpadw541 lightdm[1043]: Error terminating login1 session: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
May 05 21:51:17 thinkpadw541 systemd[1]: lightdm.service: Succeeded.
May 05 21:51:17 thinkpadw541 systemd[1]: Stopped Light Display Manager.
-- Reboot --
May 05 21:51:39 thinkpadw541 systemd[1]: Starting Light Display Manager...
May 05 21:51:39 thinkpadw541 systemd[1]: Started Light Display Manager.
May 05 21:51:42 thinkpadw541 lightdm[1137]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:51:42 thinkpadw541 lightdm[1137]: PAM adding faulty module: pam_kwallet.so
May 05 21:51:42 thinkpadw541 lightdm[1137]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:51:42 thinkpadw541 lightdm[1137]: PAM adding faulty module: pam_kwallet5.so
May 05 21:51:42 thinkpadw541 lightdm[1137]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
May 05 21:51:43 thinkpadw541 lightdm[1247]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:51:43 thinkpadw541 lightdm[1247]: PAM adding faulty module: pam_kwallet.so
May 05 21:51:43 thinkpadw541 lightdm[1247]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:51:43 thinkpadw541 lightdm[1247]: PAM adding faulty module: pam_kwallet5.so
May 05 21:51:43 thinkpadw541 lightdm[1247]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "davidphilipegil"
May 05 21:51:53 thinkpadw541 lightdm[1247]: gkr-pam: unable to locate daemon control file
May 05 21:51:53 thinkpadw541 lightdm[1247]: pam_unix(lightdm:session): session opened for user davidphilipegil by (uid=0)
May 05 21:56:13 thinkpadw541 lightdm[1772]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:56:13 thinkpadw541 lightdm[1772]: PAM adding faulty module: pam_kwallet.so
May 05 21:56:13 thinkpadw541 lightdm[1772]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:56:13 thinkpadw541 lightdm[1772]: PAM adding faulty module: pam_kwallet5.so
May 05 21:56:13 thinkpadw541 lightdm[1772]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
May 05 21:56:15 thinkpadw541 lightdm[1852]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 05 21:56:15 thinkpadw541 lightdm[1852]: PAM adding faulty module: pam_kwallet.so
May 05 21:56:15 thinkpadw541 lightdm[1852]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 05 21:56:15 thinkpadw541 lightdm[1852]: PAM adding faulty module: pam_kwallet5.so
May 05 21:56:15 thinkpadw541 lightdm[1852]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "davidphilipegil"
May 05 21:56:39 thinkpadw541 systemd[1]: Stopping Light Display Manager...
May 05 21:56:39 thinkpadw541 lightdm[817]: Error terminating login1 session: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
May 05 21:56:40 thinkpadw541 systemd[1]: lightdm.service: Succeeded.
May 05 21:56:40 thinkpadw541 systemd[1]: Stopped Light Display Manager.
lines 1-58

Magic Banana

I am a member!

Offline
Joined: 07/24/2010

Those messages were written on May 5th. Before the problem started, right? Add the option -b to have the message for the last boot:
$ journalctl -b -u lightdm

davidpgil
Offline
Joined: 08/26/2015

davidphilipegil@thinkpadw541:~$ journalctl -b -u lightdm
-- Logs begin at Sun 2019-05-05 21:46:19 EDT, end at Thu 2019-05-16 20:49:59 EDT
May 16 00:05:01 thinkpadw541 systemd[1]: Starting Light Display Manager...
May 16 00:05:03 thinkpadw541 systemd[1]: Started Light Display Manager.
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM unable to dlopen(pam_kwallet.so)
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM adding faulty module: pam_kwalle
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM unable to dlopen(pam_kwallet5.so
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM adding faulty module: pam_kwalle
May 16 00:05:05 thinkpadw541 lightdm[1335]: pam_unix(lightdm-greeter:session): s
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM unable to dlopen(pam_kwallet.so)
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM adding faulty module: pam_kwalle
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM unable to dlopen(pam_kwallet5.so
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM adding faulty module: pam_kwalle
May 16 00:05:06 thinkpadw541 lightdm[1410]: pam_succeed_if(lightdm:auth): requir
May 16 00:05:38 thinkpadw541 lightdm[1410]: gkr-pam: unable to locate daemon con
May 16 00:05:38 thinkpadw541 lightdm[1410]: pam_unix(lightdm:session): session o
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM unable to dlopen(pam_kwallet.so)
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM adding faulty module: pam_kwalle
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM unable to dlopen(pam_kwallet5.so
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM adding faulty module: pam_kwalle
May 16 00:08:13 thinkpadw541 lightdm[4066]: pam_unix(lightdm-greeter:session): s
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM unable to dlopen(pam_kwallet.so)
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM adding faulty module: pam_kwalle
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM unable to dlopen(pam_kwallet5.so
lines 1-23...skipping...
-- Logs begin at Sun 2019-05-05 21:46:19 EDT, end at Thu 2019-05-16 20:49:59 EDT. --
May 16 00:05:01 thinkpadw541 systemd[1]: Starting Light Display Manager...
May 16 00:05:03 thinkpadw541 systemd[1]: Started Light Display Manager.
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM adding faulty module: pam_kwallet.so
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 16 00:05:05 thinkpadw541 lightdm[1335]: PAM adding faulty module: pam_kwallet5.so
May 16 00:05:05 thinkpadw541 lightdm[1335]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM adding faulty module: pam_kwallet.so
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 16 00:05:06 thinkpadw541 lightdm[1410]: PAM adding faulty module: pam_kwallet5.so
May 16 00:05:06 thinkpadw541 lightdm[1410]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "davidphilipegil"
May 16 00:05:38 thinkpadw541 lightdm[1410]: gkr-pam: unable to locate daemon control file
May 16 00:05:38 thinkpadw541 lightdm[1410]: pam_unix(lightdm:session): session opened for user davidphilipegil by (uid=0)
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM adding faulty module: pam_kwallet.so
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 16 00:08:13 thinkpadw541 lightdm[4066]: PAM adding faulty module: pam_kwallet5.so
May 16 00:08:13 thinkpadw541 lightdm[4066]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM adding faulty module: pam_kwallet.so
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
May 16 00:08:13 thinkpadw541 lightdm[4151]: PAM adding faulty module: pam_kwallet5.so
May 16 00:08:13 thinkpadw541 lightdm[4151]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "davidphilipegil"
May 16 00:08:27 thinkpadw541 lightdm[4151]: gkr-pam: unable to locate daemon control file
May 16 00:08:27 thinkpadw541 lightdm[4151]: pam_unix(lightdm:session): session opened for user davidphilipegil by (uid=0)
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Magic Banana

I am a member!

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Joined: 07/24/2010

That looks fine. The problem must be "somewhere else", although LightDM is responsible for the login screen.