502 Bad Gateway nginx/1.8.0 - Fiverr

I was in hope to deliver the work for my dear customer as soon as possible but while refreshing the page, it said, "502 Bad Gateway nginx/1.8.0" - oh my, what's happening?
Error message on Fiverr

To be honest, I had never had such problem and I just wish it is going smooth so soon. After refreshing a couple minute later the website (fiverr) loading back to normal. Hooray, thanks for the team and/or machine/technical support for fixing it so quick.

I can now process the work as normal!