I’m not using G4P. Sorry for the confusion: the crash is the same, but the situation is not. However I am trying to run two sketches in the same JVM (one starts the other with PApplet.runSketch()). Similar to how G4P behaves under the hood.
It seems at the least, the issue is still persistent in 4.3.
Is this a known issue in G4P or has there been a solution? Just grasping at straws here…
Since the whole discussion 6 years ago was all about using G4P and multiple windows then perhaps you should have started a new discussion.
If your problem is about sketches using multiple windows then perhaps you might have described how you created them if not using G4P. I seriously think that might be useful information.