Summary§

When using Plasma 5.11.5 and KDE Frameworks 5.41.0 (and earlier) with a Intel X11/XFree86 driver (xf86-video-intel), some windows - specifically, those utillising GNOME/GTK+ 3 Client Side Decoration (or VTE 2.90?) - could fail to display on the screen. A taskbar entry of the window could be found, and a window preview should also display correctly. The window is not displaying, neither does it respond to any window management event: no cursor change when moving to the edge of the offending windows. Here are two instances of the issue:

Tilix
GNOME Terminal

It is also discovered that the list of word candidates for Fcitx could become invisible.

Possible Cause§

Not yet identified.

Fixed Version§

System Releases§

Tarball system releases dated 20180126 or later will no longer include the Intel DDX (xf86-video-intel), as we removed xf86-video-intel as part of the x11-base metapackage. If your system still has this package installed, upon system update, you should be prompted that xf86-video-intel is no longer needed - follow the instruction on screen to remove this package automatically.

Workaround§

A workaround has been identified - and this issue should only happen on a computer using Intel graphics (GMA, HD, UHD, etc.). To workaround this issue, you should switch to the "Modesetting" X11/XFree86 driver. To switch to this driver, simply add and apply the following configuration file with the instructions below:

Create a Custom X11 Configuration§

Using your favourite editor (assuming nano here), create a custom X11 configuration file:

sudo nano /etc/X11/xorg.conf.d/20-modesettings.conf

Input in the following content:

Section "Device"
    Identifier  "Intel Graphics"
    Driver      "modesetting"
    Option      "AccelMethod"    "glamor"
    Option      "DRI"            "3"
EndSection

And finally, Ctrl-X then Y to save the file.

Restart Your X11 Session§

Using the following command:

sudo systemctl restart display-manager.

And you should be switched to the "Modesetting" driver, and that windows should be displaying correctly.