The Animator demo in the jdk1.1p was compiled with jdk1.1p, and each of
example1, example2, example3, and example4 was loaded into appletviewer
and run. When 'Restart' was selected from the Applet menu in appletviewer,
a ClassCastException was thrown and the applet was not restarted:

// Windows

Exception occurred during event handling:
java.lang.ClassCastException:
        at Animator.paint(Animator.java:978)
        at java.awt.Component.dispatchEvent(Component.java:1175)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:109)
Exception occurred during event handling:
java.lang.ClassCastException:
        at Animator.paint(Animator.java:978)
        at Animator.update(Animator.java:943)
        at java.awt.Component.dispatchEvent(Component.java:1178)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:109)
java.lang.ClassCastException:
        at Animator.run(Animator.java:912)
        at java.lang.Thread.run(Thread.java:336)
//
// After selecting 'Reload' the following exception was thrown, but
// the applet was reloaded:

Exception occurred during event handling:
java.lang.NullPointerException: invalid peer
              at java.awt.Component.dispatchEvent(Component.java:1242)
              at java.awt.EventDispatchThread.run(EventDispatchTrhead.java:109)
//
// NOTE: These exceptions were NOT thrown when 'Restart' was selected
// while running other demos (e.g., ArcTest -- the applet restarted)>
//

// Solaris --

java.lang.ClassCastException: java.net.URL
at Animator.run(Animator.java:856)
at java.lang.Thread.run(Thread.java)
Exception occurred during event handling:
java.lang.ClassCastException: java.net.URL
at Animator.paint(Animator.java:918)
at java.awt.Component.dispatchEvent(Component.java)
at java.awt.EventDispatchThread.run(EventDispatchThread.java)

This problem is still happening in JDK11Beta3.2