I am not sure if "plasma/look & feel" is the right product/component; I'm not a KDE developer. Please kindly advise if this should be classified otherwise and how to do so. Thanks.

Created attachment 106231 [details]
Mouse pointer is corrupted. Example on konqueror drop-down menu.

Zone around pointer is corrupted - example in konqueror drop-down menu

Update:
The Desktop Theme that I have been using when I see this problem, is "Breeze".

After changing the Desktop Theme (using System Settings -> Workspace Theme -> Desktop Theme) to "Air" and logout-login into KDE, the problem doesn't seem to exist in this Theme. So, _apparently_ this is Theme dependent and the suspect is then Breeze Desktop Theme. I haven't had time for a deeper troubleshooting, though, as to test other Desktop Themes and combinations. Perhaps other users may contribute while I find time to do some more experiments on my own.  Notice, however, that just changing Cursor Themes doesn't seem to help.  Thanks.

Update: Bad news.

As said in the previous update, the problem "apparently" was theme-dependent. Now I can confirm it IS NOT, because after having restarted the system, the problem is back again. So I switched from the "Air" desktop theme to the "Breeze light", and logout-login into KDE, the problem is __apparently__ "gone" again, i.e., there is no annoying square underneath the mouse pointer/cursor. So, whether in "Air" or "Breeze", the problem is there, at least sometimes.

This makes this issue even more strange, because for some reason it seems to be possible to --at least temporarily-- mask the problem.  Whether it's because changing theme and logout-login or just simply because logout-login alone or any other crazy condition that hides the problem, I cannot tell.

Therefore, so far, it may seem that a possible workaround is to "logout-login" into KDE after (maybe) changing the Desktop Theme to any other theme. (?). Sounds crazy, but is how I am using my laptop now, until further notice.

Corrupted graphics is a video driver issue. Please report this issue to the bugtracker of your graphics driver vendor.

(In reply to Christoph Feck from comment #5)
> Corrupted graphics is a video driver issue. Please report this issue to the
> bugtracker of your graphics driver vendor.

Thank you Christoph. Would you have, nevertheless, an idea why this problem is "masked" ("fixed"??) by simply logging out of KDE and logging in again immediately ? (no restart)

That is what I am currently doing: I boot my system, log in to KDE with my password, then immediately logout from KDE and log in again, without any other action at all, and this second time I login, all is OK. This has definitely nothing to do with the selected theme, as I suspected in my previous posts.

If the problem is the driver, what could be the mechanism that "fixes" it (until next reboot) by just logging in/out/in from KDE? does login/logout/login somehow changes the environment/context, or perhaps it just allows something to restart a second time?

If the problem would be with the nvidia proprietary driver, I --and anyone else having the same issue-- may be screwed, given the known nvidia's relationship with Linux since many years.

Please discuss this with the developers of your OpenGL/video drivers.

I started to experience this problem today, after running apt-get upgrade, which upgraded to 4.10.0-28-generic on Kubuntu 16.04.2.

Before the update everything was fine, I have NVIDIA GeForce GTX 860M.

Try (In reply to Werner Mollentze from comment #8)
> I started to experience this problem today, after running apt-get upgrade,
> which upgraded to 4.10.0-28-generic on Kubuntu 16.04.2.
> 
> Before the update everything was fine, I have NVIDIA GeForce GTX 860M.

Try disabling "Enable Compositor on startup" which is under System_Settings->Display_and_Monitor->Compositor

(In reply to Werner Mollentze from comment #8)
> I started to experience this problem today, after running apt-get upgrade,
> which upgraded to 4.10.0-28-generic on Kubuntu 16.04.2.
> 
> Before the update everything was fine, I have NVIDIA GeForce GTX 860M.

Oh - I forgot ... And restart. This solved the issue for me.

(In reply to Christoph Feck from comment #5)
> Corrupted graphics is a video driver issue. Please report this issue to the
> bugtracker of your graphics driver vendor.

If it is solved by turning off Compositor and only started happening after an update that didn't include video driver updates, wouldn't that indicate a kde issue?  For me, this happened with an "apt-get upgrade" and the video drivers did not change. Some upgrade happened between my last reboot "Sun Jul  9, 2017" and the boot on "Sat Jul 29 2017" to make this happen.  

The symptoms for me are similar to the above comments however after experimenting with different settings ( e.g. Rendering, Scale, Tearing) the one thing that made the issue disappear was turning off "Enable Composter at Startup" and then restarting. 

Here's the update log for between boot "Sun Jul  9, 2017" and the boot on "Sat Jul 29 2017"

Start-Date: 2017-07-17  11:31:20
Commandline: packagekit role='update-packages'
Requested-By: REDACTED (REDACTED)
Upgrade: libgssapi3-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), vlc-bin:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), vlc-plugin-video-output:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), poppler-utils:amd64 (0.48.0-2ubuntu2, 0.48.0-2ubuntu2.1), libwind0-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), vlc-plugin-samba:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), qemu-system-mips:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), qemu-system-misc:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), qemu-system-ppc:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), vlc-plugin-qt:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libwbclient0:amd64 (2:4.5.8+dfsg-0ubuntu0.17.04.2, 2:4.5.8+dfsg-0ubuntu0.17.04.4), libheimntlm0-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), libpoppler-qt4-4:amd64 (0.48.0-2ubuntu2, 0.48.0-2ubuntu2.1), vlc-plugin-skins2:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libpoppler-qt5-1:amd64 (0.48.0-2ubuntu2, 0.48.0-2ubuntu2.1), vlc-plugin-visualization:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), vlc-l10n:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libheimbase1-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), qemu-system-x86:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), vlc-plugin-notify:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libvlc5:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), flashplugin-installer:amd64 (26.0.0.131ubuntu0.17.04.1, 26.0.0.137ubuntu0.17.04.1), libepoxy0:amd64
 (1.3.1-1ubuntu1.17.04.1, 1.3.1-1ubuntu1.17.04.2), libvirt-clients:amd64 (2.5.0-3ubuntu5.1, 2.5.0-3ubuntu5.2), qemu-user:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), libvlccore8:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libvlc-bin:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), samba-libs:amd64 (2:4.5.8+dfsg-0ubuntu0.17.04.2, 2:4.5.8+dfsg-0ubuntu0.17.04.4), ntpdate:amd64 (1:4.2.8p9+dfsg-2ubuntu1, 1:4.2.8p9+dfsg-2ubuntu1.1), apport:amd64 (2.20.4-0ubuntu4.1, 2.20.4-0ubuntu4.4), libvirt-bin:amd64 (2.5.0-3ubuntu5.1, 2.5.0-3ubuntu5.2), qemu:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), python3-apport:amd64 (2.20.4-0ubuntu4.1, 2.20.4-0ubuntu4.4), qemu-utils:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), libvirt-daemon-system:amd64 (2.5.0-3ubuntu5.1, 2.5.0-3ubuntu5.2), libhcrypto4-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), vlc:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), qemu-system-sparc:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), vlc-data:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libsmbclient:amd64 (2:4.5.8+dfsg-0ubuntu0.17.04.2, 2:4.5.8+dfsg-0ubuntu0.17.04.4), qemu-user-binfmt:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), qemu-kvm:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), libvirt0:amd64 (2.5.0-3ubuntu5.1, 2.5.0-3ubuntu5.2), vlc-plugin-video-splitter:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), code:amd64 (1.13.1-1497464373, 1.14.0-1499719149), libroken18-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), libasn1-8-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), libkrb5-26-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), qemu-system-arm:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), apport-kde:amd64 (2.20.4-0ubuntu4.1, 2.20.4-0ubuntu4.4), vlc-plugin-base:amd64 (2.2.4-14ubuntu2, 2.2.4-14ubuntu2.1), libpoppler-glib8:amd64 (0.48.0-2ubuntu2, 0.48.0-2ubuntu2.1), libpoppler64:amd64 (0.48.0-2ubuntu2, 0.48.0-2ubuntu2.1), libhx509-5-heimdal:amd64 (7.1.0+dfsg-9ubuntu1, 7.1.0+dfsg-9ubuntu1.1), qemu-block-extra:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), python3-problem-report:amd64 (2.20.4-0ubuntu4.1, 2.20.4-0ubuntu4.4), qemu-system-common:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), qemu-system:amd64 (1:2.8+dfsg-3ubuntu2.2, 1:2.8+dfsg-3ubuntu2.3), libvirt-daemon:amd64 (2.5.0-3ubuntu5.1, 2.5.0-3ubuntu5.2)
End-Date: 2017-07-17  11:32:07

Start-Date: 2017-07-17  12:41:49
Commandline: packagekit role='update-packages'
Requested-By: REDACTED (REDACTED)
Install: linux-headers-4.10.0-28-generic:amd64 (4.10.0-28.32, automatic), linux-image-4.10.0-28-generic:amd64 (4.10.0-28.32, automatic), linux-headers-4.10.0-28: amd64 (4.10.0-28.32, automatic), linux-image-extra-4.10.0-28-generic:amd64 (4.10.0-28.32, automatic) Upgrade: linux-headers-generic:amd64 (4.10.0.26.28, 4.10.0.28.29), linux-libc-dev:amd64 (4.10.0-26.30, 4.10.0-28.32), linux-image-generic:amd64 (4.10.0.26.28, 4.10.0.28.29), code:amd64 (1.14.0-1499719149, 1.14.1-1499973263), linux-generic:amd64 (4.10.0.26.28, 4.10.0.28.29)
End-Date: 2017-07-17  12:43:05

Start-Date: 2017-07-24  03:28:49
Commandline: packagekit role='update-packages'
Requested-By: REDACTED (REDACTED)
Upgrade: libexpat1-dev:amd64 (2.2.0-2, 2.2.0-2ubuntu0.1), libspice-server1:amd64 (0.12.8-2ubuntu1, 0.12.8-2ubuntu1.1), ksh:amd64 (93u+20120801-2, 93u+20120801-2ubuntu1), libexpat1:amd64 (2.2.0-2, 2.2.0-2ubuntu0.1), libexpat1:i386 (2.2.0-2, 2.2.0-2ubuntu0.1), apport:amd64 (2.20.4-0ubuntu4.4, 2.20.4-0ubuntu4.5), libxenstore3.0:amd64 (4.8.0-1ubuntu2.1, 4.8.0-1ubuntu2.2), python3-apport:amd64 (2.20.4-0ubuntu4.4, 2.20.4-0ubuntu4.5), libxen-4.8:amd64 (4.8.0-1ubuntu2.1, 4.8.0-1ubuntu2.2), libmysqlclient20:amd64 (5.7.18-0ubuntu0.17.04.1, 5.7.19-0ubuntu0.17.04.1), libmysqlclient20:i386 (5.7.18-0ubuntu0.17.04.1, 5.7.19-0ubuntu0.17.04.1), code:amd64 (1.14.1-1499973263, 1.14.2-1500506907), apport-kde:amd64 (2.20.4-0ubuntu4.4, 2.20.4-0ubuntu4.5), python3-problem-report:amd64 (2.20.4-0ubuntu4.4, 2.20.4-0ubuntu4.5)
End-Date: 2017-07-24  03:29:10

Start-Date: 2017-07-27  21:52:28
Commandline: packagekit role='update-packages'
Requested-By: REDACTED (REDACTED)
Upgrade: update-manager-core:amd64 (1:17.04.3, 1:17.04.4), xserver-common:amd64 (2:1.19.3-1ubuntu1, 2:1.19.3-1ubuntu1.1), openjdk-8-jdk:amd64 (8u131-b11-0ubuntu1.17.04.1, 8u131-b11-2ubuntu1.17.04.2), openjdk-8-jre:amd64 (8u131-b11-0ubuntu1.17.04.1, 8u131-b11-2ubuntu1.17.04.2), ruby2.3:amd64 (2.3.3-1, 2.3.3-1ubuntu0.1), xserver-xorg-core:amd64 (2:1.19.3-1ubuntu1, 2:1.19.3-1ubuntu1.1), imagemagick:amd64 (8:6.9.7.4+dfsg-3ubuntu1.1, 8:6.9.7.4+dfsg-3ubuntu1.2), libmagickwand-6.q16-3:amd64 (8:6.9.7.4+dfsg-3ubuntu1.1, 8:6.9.7.4+dfsg-3ubuntu1.2), sudo:amd64 (1.8.19p1-1ubuntu1.1, 1.8.19p1-1ubuntu1.2), google-chrome-stable:amd64 (59.0.3071.115-1, 60.0.3112.78-1), gdb:amd64 (7.12.50.20170314-0ubuntu1, 7.12.50.20170314-0ubuntu1.1), xserver-xorg-legacy:amd64 (2:1.19.3-1ubuntu1, 2:1.19.3-1ubuntu1.1), libvirt-clients:amd64 (2.5.0-3ubuntu5.2, 2.5.0-3ubuntu5.3), ubuntu-release-upgrader-qt:amd64 (1:17.04.8, 1:17.04.9), openjdk-8-jdk-headless:amd64 (8u131-b11-0ubuntu1.17.04.1, 8u131-b11-2ubuntu1.17.04.2), libvirt-bin:amd64 (2.5.0-3ubuntu5.2, 2.5.0-3ubuntu5.3), imagemagick-6.q16:amd64 (8:6.9.7.4+dfsg-3ubuntu1.1, 8:6.9.7.4+dfsg-3ubuntu1.2), python3-distupgrade:amd64 (1:17.04.8, 1:17.04.9), python3-update-manager:amd64 (1:17.04.3, 1:17.04.4), libruby2.3:amd64 (2.3.3-1, 2.3.3-1ubuntu0.1), ubuntu-release-upgrader-core:amd64 (1:17.04.8, 1:17.04.9), libvirt-daemon-system:amd64 (2.5.0-3ubuntu5.2, 2.5.0-3ubuntu5.3), libmagickcore-6.q16-3:amd64 (8:6.9.7.4+dfsg-3ubuntu1.1, 8:6.9.7.4+dfsg-3ubuntu1.2), libvirt0:amd64 (2.5.0-3ubuntu5.2, 2.5.0-3ubuntu5.3), openjdk-8-jre-headless:amd64 (8u131-b11-0ubuntu1.17.04.1, 8u131-b11-2ubuntu1.17.04.2), gdbserver:amd64 (7.12.50.20170314-0ubuntu1, 7.12.50.20170314-0ubuntu1.1), libmagickcore-6.q16-3-extra:amd64 (8:6.9.7.4+dfsg-3ubuntu1.1, 8:6.9.7.4+dfsg-3ubuntu1.2), imagemagick-6-common:amd64 (8:6.9.7.4+dfsg-3ubuntu1.1, 8:6.9.7.4+dfsg-3ubuntu1.2), libvirt-daemon:amd64 (2.5.0-3ubuntu5.2, 2.5.0-3ubuntu5.3)
End-Date: 2017-07-27  21:52:51

Start-Date: 2017-07-28  01:42:21
Commandline: packagekit role='update-packages'
Requested-By: REDACTED (REDACTED)
Upgrade: whoopsie:amd64 (0.2.55, 0.2.55.1), grub-common:amd64 (2.02~beta3-4ubuntu2.1, 2.02~beta3-4ubuntu2.2), libwhoopsie0:amd64 (0.2.55, 0.2.55.1), grub2-common:amd64 (2.02~beta3-4ubuntu2.1, 2.02~beta3-4ubuntu2.2), grub-pc:amd64 (2.02~beta3-4ubuntu2.1, 2.02~beta3-4ubuntu2.2), grub-pc-bin:amd64 (2.02~beta3-4ubuntu2.1, 2.02~beta3-4ubuntu2.2), ntpdate:amd64 (1:4.2.8p9+dfsg2ubuntu1.1, 1:4.2.8p9+dfsg-2ubuntu1.2), apache2-utils:amd64 (2.4.25-3ubuntu2.1, 2.4.25-3ubuntu2.2)
End-Date: 2017-07-28  01:42:33



$ more /etc/issue
Ubuntu 17.04 \n \l


$ kwin -v
kwin 5.9.4

$ lspci -vnn | grep VGA
00:02.0 VGA compatible controller [0300]: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06) (prog-if 00 [VGA controller])
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK107GLM [Quadro K1100M] [10de:0ff6] (rev a1) (prog-if 00 [VGA controller])


Should I open a new bug under Compositor?

See discussion at bug 382812.

Can confirm this bug, after upgrading to the latest Kubuntu 16.04 I also get this issue which ruins usability quite a lot. 
Nvidia Geforce 540M a very old card, but looks like the bug affects majority Nvidia cards. On intel Chip it all is fine.

The bug remains exactly the same, it has not been fixed, mitigated or much less resolved. Why change the status to "RESOLVED MAINSTREAM"? "Resolved" as adjective means "firmly determined to do something" and as verb "decide firmly on a course of action". It's not clear what is going to be done. The status is misleading.

After all updates possible in my system, Kubuntu 17.04 "Zesty", including nvidia driver 384.90, the symptoms and the workaround remain exactly as described four months ago.

Kicking this discussion to another one where the only "action" taken is a rude post with caps on that this is a bug of nvidia driver -while multiple users show the opposite- is not helpful at all.

Even if it where, the very minimum that a user expects, is that the devs take interest in whatever is crippling their software and enerving so many users. Ultimately, it's your software that isn't working, so at least one would expect some interest into what could be done to help, other than finger pointing somewhere else and remain in denial.