SUMMARY Flash in Firefox in full screen breaks plasmashell/Kwin, every time I put a flash video stream in full screen mode the plasmashell crashes (but no crash report is generated by the system). In order to get things working again I have to close the Firefox tab that has the flash video and run the commands: killall plasmashell && kwin && plasmashell & STEPS TO REPRODUCE 1. In Firefox browser go to a website that has a flash video, in example: https://student.testmasters.com/portal/online/Test.aspx 2. When the video starts, put it in fullscreen mode. 3. Plasmashell/KWin should crash right away OBSERVED RESULT plasmashell/Kwin crashing EXPECTED RESULT plasmashell/Kwin not to crash SOFTWARE VERSIONS System: Host: pemartins-X55U Kernel: 4.15.0-38-generic x86_64 bits: 64 Desktop: KDE Plasma 5.14.2 Distro: KDE neon User Edition 5.14 Machine: Device: laptop System: ASUSTeK product: X55U v: 1.0 serial: N/A Mobo: ASUSTeK model: X55U v: 1.0 serial: N/A UEFI: American Megatrends v: X55U.423 date: 08/06/2013 CPU: Dual core AMD E2-1800 APU with Radeon HD Graphics (-MCP-) cache: 512 KB clock speeds: max: 1700 MHz 1: 871 MHz 2: 872 MHz Graphics: Card: Advanced Micro Devices [AMD/ATI] Wrestler [Radeon HD 7340] Display Server: x11 (X.Org 1.19.6 ) drivers: ati,radeon (unloaded: modesetting,fbdev,vesa) Resolution: 1366x768@60.01hz OpenGL: renderer: AMD PALM (DRM 2.50.0 / 4.15.0-38-generic, LLVM 6.0.0) version: 3.3 Mesa 18.0.5 Audio: Card-1 Advanced Micro Devices [AMD] FCH Azalia Controller driver: snd_hda_intel Card-2 Advanced Micro Devices [AMD/ATI] Wrestler HDMI Audio driver: snd_hda_intel Sound: Advanced Linux Sound Architecture v: k4.15.0-38-generic Network: Card-1: Ralink RT5390 Wireless 802.11n 1T/1R PCIe driver: rt2800pci IF: wlp1s0 state: up mac: <filter> Card-2: Qualcomm Atheros AR8161 Gigabit Ethernet driver: alx IF: enp2s0 state: down mac: <filter> Drives: HDD Total Size: 500.1GB (8.5% used) ID-1: /dev/sda model: ST500LM012_HN size: 500.1GB Partition: ID-1: / size: 97G used: 37G (40%) fs: ext4 dev: /dev/sda5 ID-2: swap-1 size: 3.85GB used: 0.00GB (0%) fs: swap dev: /dev/sda6 RAID: No RAID devices: /proc/mdstat, md_mod kernel module present Sensors: System Temperatures: cpu: 59.0C mobo: N/A gpu: 59.0 Fan Speeds (in rpm): cpu: 3100 Info: Processes: 164 Uptime: 35 min Memory: 1310.0/3528.9MB Client: Shell (xterm) inxi: 2.3.56 ADDITIONAL INFORMATION I'm using the latest Firefox version Firefox Quantum 63.0 (64-bit).
Doesn't crash here. Please include a backtrace.
Thank you for your feedback David. Can you point me to a place where I can learn how to do a backtrace? I do not know what it is.
I was able to fix this by installing flash player in a different way. At first flash was installed as sudo apt install flashplugin-installer but for some reason the crash happened every time even after reinstall. But installing flash as sudo apt install adobe-flashplugin browser-plugin-freshplayer-pepperflash solves the issue and flash video in full screen mode no longer crashes plasmashell or KWin.
Actually some flash player streams in full screen still break at least KWin. Please let me know how to do a backtrace so I can provide the information.
Please see https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
Thank you Christoph for the help. Unfortunately I cannot get a backtrace report, it does not appear automatically and I wasn't able to get one with gdb either. Installed kdelibs5-dbg and firefox-dbg but no luck, running gdb kwin or gdb plasmashell also no luck. One of the things that happens is that the toolbars of the windows disappear which means that kwin crashed (right) but I cannot get a report. I'll try again when possible but for now just close the thread. Thank you all for your help.
Try: gdb --args kwin_x11 --replace (gdb) run [-- use kwin, wait for crash --] (gdb) thread apply all bt [-- press Enter multiple times, pastebin all output --]
Thank you very much once again Christoph for your help. So now that with your instructions I was able to generate a backtrace report, KWin never crashed again... It always has hiccups when flash comes out of fullscreen but the crashes stopped, only a couple of seconds freezes occur every time. I changed some things yesterday, in example I changed the cursor theme among other things, so probably something I changed had some collateral effect. Also after my last post I realized that mpv media player also always crashed KWin if I put it on fullscreen, but also it is not happening anymore. Only 'hiccups' just like in flash. Here is a gdb report in which I ran mpv and flash in firefox: https://pastebin.com/raw/P1jZNMRa
I had to reinstall the system and it did not happen again, all is working as expected now. As far as I can tell it was an isolated incident and not a bug.