Well, at least my Spine stuff is doing the right thing. ๐ Your logs show that it's using "Java 1.6.0_43 Apple Inc.". That is your system Java installation, not the Java bundled with Spine (which would say "OpenJDK unofficial"), so it is using the environment variable. Nothing in Spine shows that X11 popup, and you aren't using the Java bundled with Spine so I guess even the Apple Java is requiring X11, doesn't look like there is a way around it. I know you said that Spine used to run without X11, but I'm not sure how that is possible. Maybe you did a system update and Apple changed things? Maybe you started using a different system Java? You can choose which system Java to use by opening Java Preferences (use Spotlight, the magnifiying glass in the upper right of the screen, to find it).