The 502 Bad Gateway Error is an indication that something has gone wrong within the server of your application, as opposed to the client side request. At its heart, the cause is simple, two online servers are having trouble communicating. Often, simply refreshing or reloading the page (Ctrl-F5) will work, but sometimes the problem can persist for days. There are 5 main problems that cause 502 Bad Gateway responses. These include: Server failure: The gateway receives a negative result if the target server has failed completely. This can occur due to a system crash . Domain name not resolvable: The domain name is not resolving to the correct IP or it does not resolve to any IP. It is important to note that DNS changes could take same time until they are global fully propagated and active. This is dependant on the TTL, or time to live, defined per record. Webserver overload: If a webserver reaches its limit, it can't answer any more requests , the gateway then delivers the status code 502 Bad Gateway. Firewall blocks request: Firewalls can cause errors on both sides of the communication (server and client) with the forwarding of requests. Browser error: Browser extensions can also sometimes cause errors with the display of a website and generate a 502 error .
