You are getting an NPE error (nullpointer Exception)
If (231,2) doesn't get found it will return null.
So you do null.interact("Continue"); (and you can't really interact with something that doesn't exist right?)
You should stop using interfaces since the are deprecated.
Use RS2Widget instead.
You basicly to this:
RS2Widget chat1 = widgets.get(231,2)
if(chat1 != null && chat1.isVisible())
chat1.interact("Continue");
Why are you using: (Did you decompile code? Decompilers generate this kind of code)
.interact(new String[] { "Continue" });
You can just do:
.interact("Continue");
Goodluck!
Khaleesi