Not all applets are serializable, and yet appletviewer assumes that they are by allowing the user to save them. This should be controlled somehow.

See bug # 4280648: ava.lang.NullPointerException occurred by file saving with appletviewer.

To reproduce:
1) Run any applet with appletviewer.
2) Use the applet to change it's state.
3) Select Save under the Applet menu.
RESULT: It may or may not throw exceptions.

This problem occurs with JDK1.3fcs-V on Solaris 2.7.