The problem here is that HTTPS connection is created inside applet *paint* method and since SSL cerificate is not trusted the warning dialog is shown.

This happens for every repaint event and results in multiple dialogs keep showing up till the user accepts the first of them ( see Paint.png ). After dialog is accepted the expected text (and image dump) is printed in the console (see ConsoleLog.png), but the longer user wait till accepting the first dialog the more new dialogs are created and it could result in the overall system unresponsiveness. It's better demonstrated with IE. With FF in most cases it results in immediate hang probably due to difference in repainting logic these browsers use.

This is found through test case in JDK-8057955.