Steps to reproduce.
1. Enable debug options and set console as show in JCP
2. Launch a signed applet from http://sqeweb.us.oracle.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/javafx/fxfeaturesTest/fxfeaturesTest/html/SignedJNLPTest.html
3. The java console will come out with lots of information
4. Click "clear" button
5. The console will be cleared but null pointer exceptions will be thrown

Note: Try it with unsigned applet, there is no such problem


Java Plug-in 10.0.1.255
Using JRE version
User home directory =
----------------------------------------------------
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
h: display this help message
l: dump classloader list
m: print memory usage
o: trigger logging
q: hide console
r: reload policy configuration
s: dump system and deployment properties
t: dump thread list
v: dump thread stack
x: clear classloader cache
0-5: set trace level to <n>
----------------------------------------------------
Exception in runnable
java.lang.NullPointerException
at javafx.scene.control.TextInputControl.replaceText(Unknown Source)
at javafx.scene.control.TextInputControl.insertText(Unknown Source)
at com.sun.deploy.uitoolkit.impl.fx.ui.FXConsole$4.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$3.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(Unknown Source)
at com.sun.glass.ui.win.WinApplication$2$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception in runnable
java.lang.NullPointerException
at javafx.scene.control.TextInputControl.replaceText(Unknown Source)
at javafx.scene.control.TextInputControl.insertText(Unknown Source)
at com.sun.deploy.uitoolkit.impl.fx.ui.FXConsole$4.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$3.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(Unknown Source)
at com.sun.glass.ui.win.WinApplication$2$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception in runnable
java.lang.NullPointerException
at javafx.scene.control.TextInputControl.replaceText(Unknown Source)
at javafx.scene.control.TextInputControl.insertText(Unknown Source)
at com.sun.deploy.uitoolkit.impl.fx.ui.FXConsole$4.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$3.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(Unknown Source)
at com.sun.glass.ui.win.WinApplication$2$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
network: Connecting http://sqeweb.us.oracle.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/javafx/fxfeaturesTest/fxfeaturesTest/html/SignedJNLPTest.jnlp with proxy=HTTP @ www-proxy.jp.oracle.com/146.56.236.149:80
network: ResponseCode for http://sqeweb.us.oracle.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/javafx/fxfeaturesTest/fxfeaturesTest/html/SignedJNLPTest.jnlp : 304
network: Encoding for http://sqeweb.us.oracle.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/javafx/fxfeaturesTest/fxfeaturesTest/html/SignedJNLPTest.jnlp : null
network: Disconnect connection to http://sqeweb.us.oracle.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/javafx/fxfeaturesTest/fxfeaturesTest/html/SignedJNLPTest.jnlp
network: JARUpdater: update check for http://sqeweb.us.oracle.com/deployment1/deployment_6_UR_int_exec_ws/6/deployment/src/javafx/fxfeaturesTest/fxfeaturesTest/classes/signedJNLP.jar