npviewer.bin crashes consistently when exiting a flash video. To reproduce: Go to https://radar.weather.gov/radar.php?rid=mkx&product=N0R&overlay=11101111&loop=no Click on any of the "loop" links to view a radar animation. Click the browser's "back" button. There should be a pause of several seconds, after which npviewer.bin.core will appear in your home directory.
Closing, this port expired today.