Wouldn't it be simpler just to keep stacktraces in the logs? I mean, for development it's ok to see immediatly the stack trace but for a final product like this one, unless the moderators are
Java programmers, I don't think it is necessary to show them the full error message.
Just good old logging and a neutral message like "there was a problem yadda yadda, notify your admin". You could even make it so an unhandled message sent an email to the forum admin with the stack trace and all the parameters.
[originally posted on jforum.net by GreenEyed]