This exception occurs on every shutdown with Dglass.disableThreadChecks=false when we trying to call PlatformImpl.checkIdle() after Toolkit shutdown. At this moment eventThread is null.

Exception in thread "JavaFX Application Thread" java.lang.IllegalStateException: This operation is permitted on the event thread only; currentThread = JavaFX Application Thread
at com.sun.glass.ui.Application.checkEventThread(Application.java:388)
at com.sun.glass.ui.Application.isNestedLoopRunning(Application.java:489)
at com.sun.javafx.tk.quantum.QuantumToolkit.isNestedLoopRunning(QuantumToolkit.java:1115)
at com.sun.javafx.application.PlatformImpl.checkIdle(PlatformImpl.java:346)
at com.sun.javafx.application.PlatformImpl.access$700(PlatformImpl.java:49)
at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:250)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
at com.sun.glass.ui.gtk.GtkApplication.access$200(GtkApplication.java:47)
at com.sun.glass.ui.gtk.GtkApplication$5$1.run(GtkApplication.java:137)
at java.lang.Thread.run(Thread.java:724)