Goodness gracious dear sir!
From looking at that stack trace, it would seem that a plugin is being
started up, but the software which is trying to start it up has shit
itself because it can't find an attributes in the plugin that it needs.
It expects to find a data field in the plugin called "main_announcer"
but it doesn't exist.
You have software version mismatch problem.. The plugin is probably the
culprit but it could also be that the Azureus host is out of date.