Unreal Editor 5.7 UI interaction is broken on Linux for ~3 month already

General Issues and Bug Reporting
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65

I’m using Nvidia Bazzite developer edition with Wayland KDE Plasma (6.4.2), and I’ve tried numerous things described in this thread here, but when building the engine from source and running it that way the issue with the focus stealing and popups for tooltips dissapear. I just followed this post for building the Engine from source and layered clang and dotnet 10 via rpm-ostree. I’m guessing some engine display libraries are compiled properly for the distribution you are currently running.

66

this solve it for me:
create sh file for launch the engine
nano ~/Desktop/LaunchUE5.sh

#!/bin/bash

unset QT_SCALE_FACTOR
unset QT_AUTO_SCREEN_SCALE_FACTOR
unset GDK_SCALE
unset GDK_DPI_SCALE

export SDL_VIDEODRIVER=x11
export Slate.EnableSDPIScaling=0

(replace it with the path)/Engine/Binaries/Linux/UnrealEditor “$@”

make the file executable

chmod +x ~/Desktop/LaunchUE5.sh

try to launch now

~/Desktop/LaunchUE5.sh

1 Like
67

this might be of interest to people here. Updating UE5 to work on Wayland. I got it working, sort of, mostly. Swapchain issues.

1 Like
68

Still broken with worse and same issues.

69

You can’t do that:

export Slate.EnableSDPIScaling=0

You can have - or _ but no dots in linux environment variable names. Depending on your environment you might also get in trouble with the name not being in CAPS.

Setting engine-specific variables for Slate has to be done differently if that’s what you’re after.

70

tl;dr: solved wrong dropdowns placement and tooltips focus stealing in X11 by running the Editor via xwayland-satellite. Started the xwayland-satellite in one terminal window and DISPLAY=:1 SDL_VIDEODRIVER=x11 path/to/Binaries/Linux/UnrealEditor in another.

Another option was to switch to Gnome (gnome-shell / gnome-session), but I did not want to (I’m using Sway).

More details

Editor’s Wayland mode is still not usable for me: before 5.7.1 (or maybe 5.7.0?) it crashed soon after start. In 5.7.1 and 5.7.2 it runs, but all dropdowns are placed in the center of the screen, do not respond to clicks and tooltips are stealing focus.

So I have always run the editor with SDL_VIDEODRIVER=x11.

In the recent updates (5.7.2 and 5.71, not sure about 5.7.0) the inconsistency was fixed, and tooltips-dropdowns started behave the same way even with X11: center of the screen, to clicks, focus stealing.

Turned out, the Editor still works OK under Gnome Shell (even the tooltips, in the x11 mode), but I prefer Sway and I did not want to run both WMs and switch back and forth.

Turned out, the Editor also works OK (almost) via xwayland-satellite:

  • start xwayland-satellite;
  • check the logs for port number, something like Connected to Xwayland on :1 (for me it was :1 since :0 was was occupied by Xwayland);
  • run the editor with DISPLAY=<port> SDL_VIDEODRIVER=x11.

Turned out, the dropdowns also work correctly when Editor is run via labwc, but it doesn’t solve tooltips problem.

I’m using Arch btw.

71

This worked for me as well on fedora 43.

Just updated to 5.7.2 , I’m so glad this thread exists and thank you everyone!

72

Amazing! It works great! Thank a lot

I added “Skip taskbar” rule (Force → Yes) to prevent the taskbar icon to flicker whenever a tooltip is displayed