Running JavaFX and Swing on the same thread might help fix your threading issues.
There is an experimental feature in Java 8 to run JavaFX and Swing on the same thread:
https://javafx-jira.kenai.com/browse/RT-30694 http://bugs.sun.com/view_bug.do?bug_id=8015477
I think -Djavafx.embed.singleThread=true
is the command line property setting to enable the experimental single threading system.
I am not sure if the experimental feature is available in the current Java 8 builds, but I think it might be now, so you may wish to try it.
If you need more information on the experimental single threading feature, you could ask the developers on the openjfx-dev mailing list.
Java 8 has better inbuilt reporting of when code is not run on the correct thread, it's not comprehensive, but it might assist you in locating the source of your error, even if you are not using the single threading option.
Some other users running large applications merging Swing and JavaFX reported similar hard to debug threading issues, so you could check those threads to see if your issues have the same cause.