#46: JEPController:checkBundle couldn't find libawt.jnilib
Solved!
At some point, my Firefox 3.0.x on OS X 10.5 stopped opening Java applets. The failure occurs silently -- the applet simply doesn't run, with no apparent error message in the browser.
In the Console log, the output is
5/20/09 11:43:02 AM [0x0-0x104104].org...