BlueMap: Exception while rendering map

Encountered this while rendering on of my maps.

Exception in thread "Thread-8" Exception in thread "Thread-9" java.lang.IllegalArgumentException: The box is degenerate on z
        at com.google.common.base.Preconditions.checkArgument(Preconditions.java:122)
        at de.bluecolored.bluemap.core.util.AABB.<init>(AABB.java:92)
        at de.bluecolored.bluemap.core.util.AABB.<init>(AABB.java:60)
        at de.bluecolored.bluemap.core.render.hires.HiresModelManager.getTileRegion(HiresModelManager.java:124)
        at de.bluecolored.bluemap.core.render.TileRenderer.render(TileRenderer.java:49)
        at de.bluecolored.bluemap.cli.RenderTask.renderThread(RenderTask.java:162)
        at java.lang.Thread.run(Thread.java:748)
java.lang.IllegalArgumentException: The box is degenerate on z
        at com.google.common.base.Preconditions.checkArgument(Preconditions.java:122)
        at de.bluecolored.bluemap.core.util.AABB.<init>(AABB.java:92)
        at de.bluecolored.bluemap.core.util.AABB.<init>(AABB.java:60)
        at de.bluecolored.bluemap.core.render.hires.HiresModelManager.getTileRegion(HiresModelManager.java:124)
        at de.bluecolored.bluemap.core.render.TileRenderer.render(TileRenderer.java:49)
        at de.bluecolored.bluemap.cli.RenderTask.renderThread(RenderTask.java:162)
        at java.lang.Thread.run(Thread.java:748)

Not sure how I can get more information to help track down the cause, so opening this mostly just to inform that it happened, and get instructions on how to track down the issue.