Sorry you're having trouble accessing chat. There's a thread just above this one that has a lot of tips on managing java in relation to our chat room.
Check it out and see if anything in there works for you. It's trial and error, sorry to say. However, many of us have found that java 6 works best. Not to say other versions won't, but they are often finicky.
Here's the direct link:
I hope that helps! if not, let us know and we'll dig deeper.
Hope to see you back in chat soon!