A DESCRIPTION OF THE PROBLEM :
JavaFX table throws exception and stops updating.

java.lang.NullPointerException
at javafx.controls/javafx.scene.control.skin.CellSkinBase.access$100(CellSkinBase.java:56)
at javafx.controls/javafx.scene.control.skin.CellSkinBase$StyleableProperties$1.isSettable(CellSkinBase.java:166)
at javafx.controls/javafx.scene.control.skin.CellSkinBase$StyleableProperties$1.isSettable(CellSkinBase.java:161)
at javafx.graphics/javafx.scene.CssStyleHelper.transitionToState(CssStyleHelper.java:702)
at javafx.graphics/javafx.scene.Node.doProcessCSS(Node.java:9633)
at javafx.graphics/javafx.scene.Node.access$900(Node.java:398)
at javafx.graphics/javafx.scene.Node$1.doProcessCSS(Node.java:471)
at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSSImpl(NodeHelper.java:206)
at javafx.graphics/com.sun.javafx.scene.ParentHelper.superProcessCSSImpl(ParentHelper.java:95)
at javafx.graphics/com.sun.javafx.scene.ParentHelper.superProcessCSS(ParentHelper.java:65)
at javafx.graphics/javafx.scene.Parent.doProcessCSS(Parent.java:1373)
at javafx.graphics/javafx.scene.Parent.access$400(Parent.java:81)
at javafx.graphics/javafx.scene.Parent$1.doProcessCSS(Parent.java:127)
at javafx.graphics/com.sun.javafx.scene.ParentHelper.processCSSImpl(ParentHelper.java:100)
at javafx.controls/com.sun.javafx.scene.control.ControlHelper.superProcessCSSImpl(ControlHelper.java:63)
at javafx.controls/com.sun.javafx.scene.control.ControlHelper.superProcessCSS(ControlHelper.java:55)
at javafx.controls/javafx.scene.control.Control.doProcessCSS(Control.java:886)
at javafx.controls/javafx.scene.control.Control.access$000(Control.java:83)
at javafx.controls/javafx.scene.control.Control$1.doProcessCSS(Control.java:89)
at javafx.controls/com.sun.javafx.scene.control.ControlHelper.processCSSImpl(ControlHelper.java:67)
at javafx.graphics/com.sun.javafx.scene.NodeHelper.processCSS(NodeHelper.java:147)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9515)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9508)
at javafx.graphics/javafx.scene.Scene.doCSSPass(Scene.java:583)
at javafx.graphics/javafx.scene.Scene.access$3500(Scene.java:173)
at javafx.graphics/javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2502)
at javafx.graphics/com.sun.javafx.tk.Toolkit.lambda$runPulse$2(Toolkit.java:410)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:409)
at javafx.graphics/com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:436)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:518)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:498)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.pulseFromQueue(QuantumToolkit.java:491)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$11(QuantumToolkit.java:319)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:175)
at java.base/java.lang.Thread.run(Thread.java:844)