Once in a while when pressing Ctrl-C to stop the application the following exception is thrown

^CException in thread "Glass/Prism Shutdown Hook" java.lang.NoClassDefFoundError: com/sun/javafx/tk/quantum/QuantumRenderer$5
at com.sun.javafx.tk.quantum.QuantumRenderer.stopRenderer(QuantumRenderer.java:213)
at com.sun.javafx.tk.quantum.QuantumToolkit.dispose(QuantumToolkit.java:703)
at com.sun.javafx.tk.quantum.QuantumToolkit$10.run(QuantumToolkit.java:249)
Caused by: java.lang.ClassNotFoundException: com.sun.javafx.tk.quantum.QuantumRenderer$5
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 3 more