I have the same issue. I have Virtualbox running as well. I'm not switching between users. Just standby and resume. Here are some parts of several logfiles. auth.log ====================================== Mar 12 16:36:33 BN pkexec: pam_systemd(polkit-1:session): Cannot create session: Already running in a session Mar 12 16:36:33 BN pkexec[20336]: bart: Executing command [USER=root] [TTY=unknown] [CWD=/home/bart] [COMMAND=/usr/lib/unity-settings-daemon/usd-backlight-helper --set-brightness 7126] Mar 12 16:36:45 BN lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory Mar 12 16:36:45 BN lightdm: PAM adding faulty module: pam_kwallet.so Mar 12 16:36:45 BN lightdm: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory Mar 12 16:36:45 BN lightdm: PAM adding faulty module: pam_kwallet5.so Mar 12 16:36:45 BN lightdm: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0) Mar 12 16:36:45 BN systemd-logind[1178]: New session c32 of user lightdm. Mar 12 16:36:45 BN lightdm: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory Mar 12 16:36:45 BN lightdm: PAM adding faulty module: pam_kwallet.so Mar 12 16:36:45 BN lightdm: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory Mar 12 16:36:45 BN lightdm: PAM adding faulty module: pam_kwallet5.so Mar 12 16:36:45 BN lightdm: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "bart" Mar 12 16:36:49 BN lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm Mar 12 16:36:49 BN dbus[1153]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.498" (uid=109 pid=20527 comm="/usr/lib/x86_64-linux-gnu/indicator-bluetooth/indi") interface="org.freedesktop.DBus.Properties" member="GetAll" error name="(unset)" requested_reply="0" destination=":1.380" (uid=0 pid=10380 comm="/usr/lib/bluetooth/bluetoothd ") Mar 12 16:36:49 BN dbus[1153]: [system] Rejected send message, 2 matched rules; type="method_call", sender=":1.498" (uid=109 pid=20527 comm="/usr/lib/x86_64-linux-gnu/indicator-bluetooth/indi") interface="org.freedesktop.DBus.ObjectManager" member="GetManagedObjects" error name="(unset)" requested_reply="0" destination="org.bluez" (uid=0 pid=10380 comm="/usr/lib/bluetooth/bluetoothd ") Mar 12 16:37:15 BN sudo: bart : TTY=pts/22 ; PWD=/home/bart ; USER=root ; COMMAND=/usr/bin/zsh Mar 12 16:37:15 BN sudo: pam_unix(sudo:session): session opened for user root by (uid=0) Mar 12 16:38:58 BN pkexec: pam_unix(polkit-1:session): session opened for user root by (uid=1000) Mar 12 16:38:58 BN pkexec: pam_systemd(polkit-1:session): Cannot create session: Already running in a session Mar 12 16:38:58 BN pkexec[22237]: bart: Executing command [USER=root] [TTY=unknown] [CWD=/home/bart] [COMMAND=/usr/lib/update-notifier/package-system-locked] Xorg.0.log ====================================== [ 23362.625] (II) AIGLX: Suspending AIGLX clients for VT switch [ 23364.120] (--) synaptics: DLL075B:01 06CB:76AF Touchpad: touchpad found [ 23368.192] (II) AIGLX: Resuming AIGLX clients after VT switch [ 23369.699] (II) Quirked EDID physical size to 0x0 cm [ 23369.699] (II) modeset(0): EDID vendor "SAM", prod id 1485 [ 23369.699] (II) modeset(0): Using hsync ranges from config file [ 23369.699] (II) modeset(0): Using vrefresh ranges from config file [ 23369.699] (II) modeset(0): Printing DDC gathered Modelines: [ 23369.699] (II) modeset(0): Modeline "1920x1080"x0.0 148.50 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (67.5 kHz eP) [ 23369.699] (II) modeset(0): Modeline "1280x720"x0.0 74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync (45.0 kHz e) [ 23369.699] (II) modeset(0): Modeline "1920x1080i"x0.0 74.25 1920 2448 2492 2640 1080 1084 1094 1125 interlace +hsync +vsync (28.1 kHz e) [ 23369.699] (II) modeset(0): Modeline "1920x1080i"x0.0 74.25 1920 2008 2052 2200 1080 1084 1094 1125 interlace +hsync +vsync (33.8 kHz e) [ 23369.699] (II) modeset(0): Modeline "1280x720"x0.0 74.25 1280 1720 1760 1980 720 725 730 750 +hsync +vsync (37.5 kHz e) [ 23369.699] (II) modeset(0): Modeline "720x576"x0.0 27.00 720 732 796 864 576 581 586 625 -hsync -vsync (31.2 kHz e) [ 23369.699] (II) modeset(0): Modeline "720x480"x0.0 27.00 720 736 798 858 480 489 495 525 -hsync -vsync (31.5 kHz e) [ 23369.699] (II) modeset(0): Modeline "800x600"x0.0 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e) [ 23369.699] (II) modeset(0): Modeline "800x600"x0.0 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz e) [ 23369.699] (II) modeset(0): Modeline "640x480"x0.0 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e) [ 23369.699] (II) modeset(0): Modeline "1024x768"x0.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e) [ 23369.699] (II) modeset(0): Modeline "1600x1200"x0.0 162.00 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync (75.0 kHz e) [ 23369.699] (II) modeset(0): Modeline "1280x1024"x0.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e) [ 23369.699] (II) modeset(0): Modeline "1280x960"x0.0 108.00 1280 1376 1488 1800 960 961 964 1000 +hsync +vsync (60.0 kHz e) [ 23369.699] (II) modeset(0): Modeline "1280x800"x0.0 71.00 1280 1328 1360 1440 800 803 809 823 +hsync -vsync (49.3 kHz e) [ 23369.699] (II) modeset(0): Modeline "1440x900"x0.0 88.75 1440 1488 1520 1600 900 903 909 926 +hsync -vsync (55.5 kHz e) [ 23369.699] (II) modeset(0): Modeline "1680x1050"x0.0 119.00 1680 1728 1760 1840 1050 1053 1059 1080 +hsync -vsync (64.7 kHz e) [ 23369.699] (II) modeset(0): Modeline "1920x1080"x0.0 74.25 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync (27.0 kHz e) [ 23369.699] (II) modeset(0): Modeline "1440x480i"x0.0 27.00 1440 1478 1602 1716 480 488 494 525 interlace -hsync -vsync (15.7 kHz e) [ 23369.699] (II) modeset(0): Modeline "1440x576i"x0.0 27.00 1440 1464 1590 1728 576 580 586 625 interlace -hsync -vsync (15.6 kHz e) [ 23369.734] [dix] couldn't enable device 14 I hope this helps.