During the test of applets on the new macOS 10.12 Sierra, customer have
discovered that the JVM continuously throw a NullPointerException (see the
They have seen the problem both 8u10 and the upcoming 8u111 b10 and 8u112
b04, and the problem could be reproduced on all their own applets as well as
https://www.java.com/verify, especially when you closed down the applet or
navigated away from the site in the web browser.
They could not give a specific flow because the problem is not consistent.
While the applets still works, the dialogs will be annoying for the end user.