I just installed Kubuntu 14.04 (+ updates) on a 3-monitor system. However, once KDE starts, the mouse-pointer disappears on 2 of the screens. 1. I set up the 3 screens to be correctly in a line, in xorg.conf. This then works precisely as it should within XFCE. It also works exactly right at the LightDM login screen: I can move the cursor correctly across all 3 monitors, and the login dialog box moves with it. 2. When I start KDE, the 2 left monitors blink and flash a lot for about 5 seconds, then everything settles down and looks normal. Excepting that the mouse-pointer is invisible on 2 screens. I can still move windows around, and click (by dead reckoning) - just the pointer itself is not drawn. 3. I've tried a few things, which may help with debugging. * This is KDE-specific: if I run Unity or XFCE, there's no problem. * This happens in Kubuntu 14.04 (KDE 4.4.13), and in Utopic Alpha. * It only happens after login. * I'm using a default KDE setup (tested in guest-mode with a temporary account) * It doesn't help to change cursor-theme. * It doesn't make any difference if I login with desktop-effects disabled. * This exact system worked fine in Mageia 3. * I'm using the Xorg 1.15.1 radeon driver, with kernel 3.13.0-32. It's a Radeon HD 6450 graphics card, with 3 digital outputs. Lastly, I'm a little puzzled about the version numbers. Systemsettings->About KDE shows version 4.13.2, however the most recent numbered version I can choose in this bug report is 4.11.10 (so I picked the one higher than that, i.e. git-master; sorry if I got this wrong). I hope this is a helpful bug report; please let me know if there are any further experiments I can do to assist.
If I log into XFCE, and then from a running XFCE, start konsole and then type kwin --replace plasma-desktop & startkde then I can get a working hybrid session, in which I do not observe this bug. Does this shed any light?
Plasma version 4.11.10 is shipped with KDE SC 4.13.2, because it was feature-frozen since 4.11.0.
(In reply to Christoph Feck from comment #2) > Plasma version 4.11.10 is shipped with KDE SC 4.13.2, because it was > feature-frozen since 4.11.0. Thanks for the explanation. For future reference, how could I have found this out to report it correctly? I just looked at the KDE version in systemsettings. Is there any more info you need that would help debug this? Is it in any way relevant that of the 3 monitors, the 2 that don't show the mouse pointer under KDE are comparatively old ones that need a manual modeline in xorg.conf?
It might be caused by drivers not supporting larger cursors. Try to change the cursor size to a (small) fixed size. If no fixed size is set, it tries to scale the cursor depending on screen resolution. Related: bug 196294.
(In reply to Christoph Feck from comment #4) > It might be caused by drivers not supporting larger cursors. Try to change > the cursor size to a (small) fixed size. If no fixed size is set, it tries > to scale the cursor depending on screen resolution. > Related: bug 196294. Thanks for the idea, but I'm afraid it doesn't help. I tried a new KDE session with multiple different cursors, including the Oxygen default, the KDE classic, and various ones at fixed sizes of 24 and even the Handhelds at 12. This doesn't help. On the other hand, I've got no problem switching the cursors around under any other DE, and indeed, I can change themes and sizes in many permutations within the "hybrid" XFCE/KDE session I'm currently running (see comment 1) I suspect that when KDE first starts up, it does something "weird" to the graphics card which makes the left hand pair of monitors flash about 10 times in 3 seconds, as if they are being "auto-detected". XFCE doesn't do this.
Hm, okey. I can reassign to kscreen developers, maybe they have an idea. Otherwise without access to a system where it can be reproduced, it will be hard to fix. Assuming you have installed and enabled kscreen (should be default in 14.04, as far as I know). If not, please add a comment.
(In reply to Christoph Feck from comment #6) > Hm, okey. I can reassign to kscreen developers, maybe they have an idea. > Otherwise without access to a system where it can be reproduced, it will be > hard to fix.> > Assuming you have installed and enabled kscreen (should be default in 14.04, > as far as I know). If not, please add a comment. Yes, I do have kscreen installed (as part of the default). I experimented quite a lot with logging in and out of guest sessions in various ways, even trying to run /usr/bin/startkde one line at a time from within a terminal in XFCE. There is one clear experimental result: If I move /usr/lib/kde4/plugins/kscreen out of the way, and then start KDE, everything works right. On the other hand, when I put it back, the breakage occurs. So kscreen, at KDE-startup is responsible. Although I can't give you direct access to this system, I'm very happy to help debug the problem and run experiments as requested. Also, before I temporarily disabled kscreen, I ran kscreen-console to see if there was anything interesting. I'll attach it. Incidentally, I've got no problem re-arranging the monitors using arandr. This is definitely something that kscreen does.
Created attachment 87869 [details] output from kscreen-console
Created attachment 87870 [details] second experiment Interestingly, if I have the KDE session already running, and *then* restore /usr/lib/kde/plugins/kscreen, and then go to system-settings and move the monitors around within the GUI, it works as it is supposed to, with no problematic side-effects. (Output of kscreen-console attached).
I had a similar problem but I'm not 100% sure it's the same bug. Below I describe my situation in case it may work as a work-around for someone. In short: For me the problem was solved by replacing lightdm with kdm as login manager. Some more details: Kubuntu 14.04.3 + Kubuntu KDE backports PPA (all updates applied as of today). I installed the system with a single monitor attached and then moved the machine and changed to a dual monitor setup. The monitors where automatically configured and showed a shared desktop when the system started (i.e. not the same desktop mirrored). The mouse pointer was gone though... It showed neither in the login screen nor when the desktop was loaded (same for all screens). I could figure out roughly where the mouse pointer was though due to desktop effects or by noticing where the pop-up menu appeared when right-clicking. I tried many tips from other reports but nothing helped me. I also tried to disable the backports and install older versions of kscreen - this seemed to help at one point but after a reboot the problem was back. sudo apt-get install kdm In the configuration that follows, make sure to mark kdm your preferred login manager.
Thank you for the bug report. As this report hasn't seen any changes in 5 years or more, we ask if you can please confirm that the issue still persists. If this bug is no longer persisting or relevant please change the status to resolved.
I've not seen this in ages. Marking as resolved.