Yes, OnBux is down for quite some time already and one could only wonder - was it intentionally done? Was the hard-clicked money earned by their users too lucrative to be taken (scammed) so that they purposely close down the site?
Was there an issue with their hosting? But many would conclude that it's a scam attempt.
Goodbye OnBux, you've been good actually - except for the remaining credit you didn't pay up.