This is a known issue and I believe we have submitted a PR to the JavaFX project that should fix it. Not sure of the status. I actually thought we had merged it and the problem was solved. @vlaaad or @mats.gisselson can you confirm?
Cool, thanks for the heads up. It’s just one of those things that are slightly annoying, and I finally got around to letting you guys know about it.
Fix we contributed to JavaFX was about exceptions appearing randomly, related to menu bar. This exception is different — it’s related to change we did to make tabs reorderable (which is also buggy in JavaFX).