I'm getting an error any time I try to export my project from Spine for any version above 1.8.35. (I've tried 1.8.36, 37, and 40).

This is the call stack in spine.log

java.lang.IllegalStateException: Array is empty.
at gj.c(SourceFile:237)
at pu.a(SourceFile:537)
at pu.a(SourceFile:241)
at qr.R(SourceFile:394)
at qo.b(SourceFile:110)
at qp.a(SourceFile:85)
at Ea.a(SourceFile:191)
at Ea.b(SourceFile:186)
at DR.run(SourceFile:164)
at Ea.f(SourceFile:199)
at DX.a(SourceFile:154)
at com.esotericsoftware.spine.editor.Editor.b(SourceFile:777)
at ac.a(SourceFile:254)
at ac.e(SourceFile:222)
at kC.e(SourceFile:98)
at ah.run(SourceFile:188)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

I've also attached a cut down version of the project (which still crashes).