Title bar for windows disappears randomly. OS freezes? Weird bug.

[singh.zn]

So I'm experiencing random freezes/crashes with Kubuntu 18.04 where the title bar disappears randomly for all my open windows and the OS becomes unresponsive. The mouse pointer works and I can still interact with the current active application but clicking the application launcher/dock doesn't do anything. The keyboard doesn't work either. This usually happens when I keep rapidly switching from one virtual desktop to the other with apps open on them or when I minimize/maximize a playing video on youtube. I've tried switching from Nvidia display drivers to the Nouveau drivers and the issue still persists. What can I do to fix this?

FYI I'm dual-booting with Kubuntu running natively and Win 10 on a second partition.

Any help would be much appreciated

My setup-

Kubuntu 18.04 with latest updates
KDE Frameworks 5.44.0
Qt 5.9.5
xcb windowing system

CPU: Intel i5 6600
GPU: Nvidia Geforce GTX 1070 Ti
RAM: 16 GB DDR4 2600 Mhz
Storage: 250 GB SSD, 2 x 500 GB HDD.

[jglen490]

Please post the results of

inxi -Fx

from a konsole session into a CODE box (the #button) here.

[singh.zn]

So this utility wasn't installed the first time I tried executing it.

Command 'inxi' not found, but can be installed with:

sudo apt install inxi

Post installation:

System:    Host: zn-KB-1333 Kernel: 4.18.0-18-generic x86_64 bits: 64 gcc: 7.3.0
          Desktop: KDE Plasma 5.12.7 (Qt 5.9.5) Distro: Ubuntu 18.04.2 LTS
Machine:   Device: desktop Mobo: MSI model: H110M PRO-VD (MS-7996) v: 1.0 serial: N/A
          UEFI: American Megatrends v: 2.30 date: 11/05/2015
CPU:       Quad core Intel Core i5-6600 (-MCP-) arch: Skylake-S rev.3 cache: 6144 KB
          flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 26496
          clock speeds: max: 3900 MHz 1: 1018 MHz 2: 3339 MHz 3: 3237 MHz 4: 3228 MHz
Graphics:  Card: NVIDIA GP104 [GeForce GTX 1070 Ti] bus-ID: 01:00.0
          Display Server: x11 (X.Org 1.19.6 ) drivers: nvidia (unloaded: modesetting,fbdev,vesa,nouveau)
          Resolution: 2560x1440@59.95hz
          OpenGL: renderer: GeForce GTX 1070 Ti/PCIe/SSE2 version: 4.6.0 NVIDIA 390.116 Direct Render: Yes
Audio:     Card-1 Intel 100 Series/C230 Series Family HD Audio Controller driver: snd_hda_intel bus-ID: 00:1f.3
          Card-2 NVIDIA GP104 High Definition Audio Controller driver: snd_hda_intel bus-ID: 01:00.1
          Sound: Advanced Linux Sound Architecture v: k4.18.0-18-generic
Network:   Card-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
          driver: r8169 v: 2.3LK-NAPI port: d000 bus-ID: 02:00.0
          IF: enp2s0 state: down mac: 4c:cc:6a:09:a9:52
          Card-2: Atheros AR9271 802.11n driver: ath9k_htc usb-ID: 001-002
          IF: wlxec086b1849a7 state: N/A mac: N/A
Drives:    HDD Total Size: 1730.4GB (0.6% used)
          ID-1: /dev/sda model: SanDisk_Ultra_II size: 480.1GB temp: 30C
          ID-2: /dev/sdb model: Samsung_SSD_850 size: 250.1GB temp: 0C
          ID-3: /dev/sdc model: ST3500412AS size: 500.1GB temp: 31C
          ID-4: /dev/sdd model: ST3500412AS size: 500.1GB temp: 29C
Partition: ID-1: / size: 20G used: 9.2G (51%) fs: ext4 dev: /dev/sdb5
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   System Temperatures: cpu: 39.5C mobo: 29.8C gpu: 0.0:48C
          Fan Speeds (in rpm): cpu: N/A
Info:      Processes: 223 Uptime: 4 min Memory: 1362.2/16003.1MB Init: systemd runlevel: 5 Gcc sys: 7.3.0
          Client: Shell (bash 4.4.191) inxi: 2.3.56

Hope that helps.

[jlittle]

The window manager, "kwin" , or KDE plasma, "plasmashell", or both, have crashed. X is still running.

One possibility is that some user configuration file is corrupt. You could try adding another user, and see if the problems persist. If they don't, then you could start renaming files and directories in ~/.config and ~/.local to isolate the trouble.

You could try and limp along by restarting those processes, from a Linux console via ctrl-alt-f2 if necessary (in which case setting the DISPLAY environment variable with export DISPLAY=:0). I did that for months some years ago. You'd have to determine the correct command for each, I don't know them now.

But it may be that your quickest way out of trouble is a reinstall.

Sent from my Vodafone Smart ultra 6 using Tapatalk

[jglen490]

Based on this

Drives:    HDD Total Size: 1730.4GB (0.6% used)
         ID-1: /dev/sda model: SanDisk_Ultra_II size: 480.1GB temp: 30C
         ID-2: /dev/sdb model: Samsung_SSD_850 size: 250.1GB temp: 0C
         ID-3: /dev/sdc model: ST3500412AS size: 500.1GB temp: 31C
         ID-4: /dev/sdd model: ST3500412AS size: 500.1GB temp: 29C
Partition: ID-1: / size: 20G used: 9.2G (51%) fs: ext4 dev: /dev/sdb5

you have pretty small Linux installation and no SWAP partition, but possibly a swap file. I agree with jlittle's assessment that something has crashed, possibly due to space or memory issues while running your VMs.

[oshunluvr]

16 Gigs of RAM an 49% free drive space I doubt it's a memory/swap error. Almost certainly desktop effects or KWIN crashing. Maybe try a different rendering backend via System Setting > Display and Monitor > Compositor