A DESCRIPTION OF THE PROBLEM :
We've seen this a few times in the real world, it looks like activatedTooltip can be null when the activationTimer finishes

java.lang.AssertionError
at javafx.scene.control.Tooltip$TooltipBehavior.lambda$new$0(Tooltip.java:869)
at javafx.animation.Animation.finished(Animation.java:1131)
at javafx.animation.AnimationAccessorImpl.finished(AnimationAccessorImpl.java:49)
at com.sun.scenario.animation.shared.SingleLoopClipEnvelope.timePulse(SingleLoopClipEnvelope.java:103)
at javafx.animation.Animation.doTimePulse(Animation.java:1101)
at javafx.animation.Animation$1.lambda$timePulse$0(Animation.java:186)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.animation.Animation$1.timePulse(Animation.java:185)
at com.sun.scenario.animation.AbstractMasterTimer.timePulseImpl(AbstractMasterTimer.java:344)
at com.sun.scenario.animation.AbstractMasterTimer$MainLoop.run(AbstractMasterTimer.java:267)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:558)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:542)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulseFromQueue(QuantumToolkit.java:535)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$11(QuantumToolkit.java:341)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at com.sun.glass.ui.win.WinApplication._runLoop(WinApplication.java)
at com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
at java.base/java.lang.Thread.run(Unknown Source)



FREQUENCY : rarely