Can't Open in KDE 6

[victopteryx]

Expected Function: Run program from terminal with 'java -jar vsmodelcreator.jar'

Actual Function: Program does not run. Received this error:

Exception in thread "main" java.lang.ExceptionInInitializerError
at com.jtattoo.plaf.AbstractLookAndFeel.(AbstractLookAndFeel.java:41)
at at.vintagestory.modelcreator.Start.main(Unknown Source)
Caused by: java.awt.HeadlessException:
No X11 DISPLAY variable was set,
or no headful library support was found,
but this program performed an operation which requires it.
at java.desktop/sun.awt.HeadlessToolkit.getScreenSize(HeadlessToolkit.java:186)
at com.jtattoo.plaf.JTattooUtilities.(JTattooUtilities.java:44)
... 2 more

Running Fedora Linux, KDE Plasma. Current Plasma builds use Wayland.

Java version is:

openjdk 21.0.10 2026-01-20
OpenJDK Runtime Environment (Red_Hat-21.0.10.0.7-2) (build 21.0.10+7)
OpenJDK 64-Bit Server VM (Red_Hat-21.0.10.0.7-2) (build 21.0.10+7, mixed mode, sharing)

[victopteryx]

Also tried this with the liked Temurin Java version. Same error.