For example, you have only one monitor. Steps to reproduce: 1) Unplug your monitor 2) Plug it back. -> Screen may be black (nvidia). Or mouse cursor may disappear(nouveau). In xfce4-display-settings it is impossible to turn on monitor (there is no tick "Set display as main"). System becomes unusable, the only wayout - to restart display manager. Unreproducible in MATE and other DEs, so it is xfce's problem. Moreover if you unplugged and plugged your monitor back and rhe only mouse cursor disappeared - switching to tty1 and then back to your X server - your screnn will be absolutely black. In other words XFCE does not recognize the monitor which was plugged back. Try 1 and 2 steps 2-3 times, as for me the bugs reproduces in the first iteration.
Created attachment 6591 screenshot1
Created attachment 6592 screenshot2 with descriptions I was blaming Nvidia before, I have conducted talks with them - but they were not able to reproduce bug. I'm using Linux Mint 17.3 XFCE (as you see fresh install), kernel 3.19 and 4.2, xserver is 1.17 (lts-vivid) (I have also tried with 1.15)
I have same problem! "In other words XFCE does not recognize the monitor which was plugged back". my desktop: M4A88T-I DELUXE, 4xAMD Athlon(tm)II X4 610e, Radeon HD 4250, BenQ V2210 Eco, HDMI. Debian Stretch and Archlinux. Xfce4.12, xorg-server 1.18, lightdm, GL_VERSION: 3.0 Mesa 11.2.1, Gallium 0.4 on AMD RS880 (DRM 2.43.0, LLVM 3.7.1), kernel 4.4 - 4.5. if unplug/plug my monitor on VT7 then xfce4 does not find the monitor signal HDMI-0 on VT7. but switch to virtual terminals operating normally (VT1-VT6 by ctrl+alt+F?), and the monitor turns. MATE, LXDE, pure X, console do not have this problem. this problem repeats in a case with several monitors. I like Xfce4, please help us!
It seems this bug in the package xfce4-settings. Bug appears when the daemon xfsettigsd is running. when xfconfd works only bug is absent.
Created attachment 6661 Situation with settingsd disabled after trying to re-enable the 3rd screen, 2nd scree got switched off as well
Created attachment 6662 This is how it should look like instead, unfortunately even if you reach this the settingsd will diable it again if you don't run an xrandr script fast enough.
I have a severe case of ME TOO here... I have a setup with 3 displays and it seems once you disabled (powered down/ unplugged) one of the displays you can not re-enable it. The Login/Lock Screen however enables all displays in 100% of the cases. Unfortunately once once you're logged in, the problematic display is beeing disabled again. This is also the case after rebooting the machine or restarting the window manager. Only trying for what it seems a gazillion times to re-enable the 3rd screen in the display config screen, interspersed with calling xrandr with the command below I can hit a timing where the display doesn't get disabled again immediately. xrandr --output VGA-0 --off --output DP-5 --off --output DP-6 --mode 3840x2160 --pos 6080x0 --rotate normal --output DP-4 --mode 3200x1800 --pos 0x0 --rotate normal --output DP-3 --scale 1.5x1.5 --mode 1920x1200 --pos 3200x0 --rotate normal --output DP-2 --off --output DP-1 --off --output DP-0 --off This is not necessarily the case in a 2 display configuration. There I can quite often recover by just locking the screens and logging back in once the login screen has power cycled both displays. Only infrequently I have as severe problems as in the 3 diplay config. I just tried the above suggestion, killing the settings daemon triggered another longstanding bug: My font settings went haywire, all the menus, text under the icons, the text in the terminal windows etc turned microscopically small. Trying to re-enable the 3rd display caused the 2nd display to be disabled as well. (See the attached screenshot) neuffer@charion:~$ ps auxwww | grep xfset neuffer 5650 0.0 0.0 365708 17208 ? Ssl 08:54 0:00 xfsettingsd --display :0.0 --sm-client-id 29b40e0b7-f989-49a0-8d5d-722c26339e27 neuffer 13861 0.0 0.0 15752 944 pts/19 S+ 09:25 0:00 grep --color=auto xfset neuffer@charion:~$ kill 5650 neuffer@charion:~$ ps auxwww | grep xfset neuffer 13869 0.0 0.0 15752 928 pts/19 S+ 09:25 0:00 grep --color=auto xfset Re-starting the daemon brought the warning below: neuffer@charion:~$ xfsettingsd --display :0.0 --sm-client-id 29b40e0b7-f989-49a0-8d5d-722c26339e27 neuffer@charion:~$ (xfsettingsd:13873): xfsettingsd-WARNING **: Failed to configure CRTC 731.
Problably important in the context above: default-display-manager:/usr/sbin/lightdm
This seems to be related: https://bugzilla.xfce.org/show_bug.cgi?id=12184
My display manager is MDM, so I gues it is DM independent, nevertheless both are forks of GDM
I have same issue, with intel chipset. The workaround I use is: ctrl-alt-f1 for text console, then I do: export DISPLAY=:0; sleep 1s; xrandr --auto And then i do: ctrl-alt-7 so xrandr --auto is run while i have that screen up. This started to happen after I switched my 2x24" dell screens (vga+dvi) with a big ultrawide screen (3440x1440) on display port.
I believe this is a duplicate of bug 11107
this patch fixes it for me: https://bugzilla.xfce.org/show_bug.cgi?id=11107#attach_6590
Can you confirm that #11107 patch fix you issue too ? It's available in xfce4-settings 4.12.1.
I can at least say I havn't seen it in quite a while. I still have another issue: When I get the initial Login Screen, the displays are setup correctly in the proper native resolution and order. then after login the order gets changed and I have to run: xrandr --output VGA-0 --off --output DP-5 --off --output DP-6 --mode 3840x2160 --pos 7040x0 --rotate normal --output DP-4 --mode 3200x1800 --pos 0x0 --rotate normal --output DP-3 --scale 2x2 --mode 1920x1200 --pos 3200x0 --rotate normal --output DP-2 --off --output DP-1 --off --output DP-0 --off
I can confirm that patch for 11107 fixes this issue, thanks!
Closing, thank you.