Does not start with OpenJDK

JAVA_HOME and PATH are set, but GanttProject does not start.

How do I fix this?

C:\Program Files (x86)\GanttProject-2.8>javac --version
javac 13.0.1

C:\Program Files (x86)\GanttProject-2.8>java --version
openjdk 13.0.1 2019-10-15
OpenJDK Runtime Environment (build 13.0.1+9)
OpenJDK 64-Bit Server VM (build 13.0.1+9, mixed mode, sharing)

C:\Program Files (x86)\GanttProject-2.8>javac --version
javac 13.0.1

I tried for so long and now just after I wrote this I found the BAT-file…

So starting using the BAT does work. Starting using the EXE does not.

This is discussed here:

can you try this? Gantt Project will not open on Windows 10, with Java 8+ - fixed with latest JRE 8.231