SUMMARY Some windows, notably Google Chrome (any version from 2018 or later) and VMware Workstation (versions 12-15) simply stop updating sometimes under KDE. The problematic window seems to ignore all input, as if it were hung, but if you click on any other window, then back to the problematic window, the updates appear. Since the exact same symptom happens to different applications, I believe the culprit is KDE. For example, when a Chrome window develops the problem, you can click a web link (say, to google.com) and absolutely nothing happens in the Chrome window. But if you click to activate some other window, then click back the Chrome window again, the Chrome window suddenly updates to google.com. (That is, the click on the link DID have an effect on the window's state, but it wasn't visible -- the effect didn't show up until the Chrome window lost focus and regained focus.) The problem usually happens to just ONE window at a time. I think I have seen it happen to Konsole also, but I'm not sure. This problem happens in Kubuntu 16.04 and 18.04. It's been happening for years. STEPS TO REPRODUCE 1. The problem shows up randomly :-(, but when it happens, here is what to do. 2. Activate the problematic window and try to make some kind of obvious, visible change. 3. Nothing visible happens in the window. 4. Click some OTHER window on screen, then click the problematic window. 5. The change you tried to make in step 2 instantly becomes visible. 6. The problem remains until I close the window. OBSERVED RESULT Changes to the problematic window have no effect until you click away and click back. EXPECTED RESULT Changes to the problematic window should happen immediately. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 18.04 (Ubuntu 18.04.2 LTS, kernel 4.15.0-54-generic) KDE Plasma Version: 5.12.7 KDE Frameworks Version: 5.44.0 Qt Version: 5.9.5 ADDITIONAL INFORMATION
The problematic window also refreshes if I minimize it to the taskbar and then un-minimize it.
The problematic window also refreshes if I use the KDE Pager to switch to a different virtual desktop and then switch back.
This command $ kquitapp5 plasmashell && kstart5 plasmashell does not fix the problem.
I'm also seeing a similar problem with Chromium on KDE neon 5.17.0. Randomly minimizing and unminimizing the affected window or other windows sometimes fixes it. What definitely never fixes it for me is switching virtual desktops. Operating System: KDE neon 5.17 KDE Plasma Version: 5.17.0 KDE Frameworks Version: 5.63.0 Qt Version: 5.13.1 Kernel Version: 5.0.0-31-generic OS Type: 64-bit Processors: 4 × Intel® Core™ i5-2430M CPU @ 2.40GHz Memory: 3.8 GiB of RAM Graphics card: Geforce GT540M or so, plus some Intel integrated thing (laptop, Optimus)
Happens all the time to me in Konsole. There the screen also updates when I press the Enter key. (Switching away and back to the Konsole window also makes it update). Debian Konsole 19.08.1 KDE Frameworks 5.62.0 Qt 5.12.5 (built against 5.12.5) The xcb windowing system
Update 3 years after filing this bug report: The problem still occurs in Kubuntu 22.04.1 LTS. It still affects VMware Workstation Pro (version 16.2.5) and Google Chrome (version 108.0.5359.124). I have found that restarting kwin clears up the symptoms for VMware Workstation. (I haven't tried it when Chrome misbehaves.) $ kwin --replace > /dev/null < /dev/null & Currently the problem happens every few days.