HTTP Error 502 Bad Gateway, 503 Service Unavailable
This error is usually due to improperly configured proxy servers. However, the problem may also arise when there is poor IP communication amongst back-end computers, when the client’s ISP is overloaded, or when a firewall is functioning improperly.
The first step in resolving the issue is to clear the client’s cache. This action should result in the a different proxy being used to resolve the web server’s content.
503 Service Unavailable
This error occurs when the server is unable to handle requests due to a temporary overload or due to the server being temporarily closed for maintenance. The error signifies that the server will only temporarily be down. It is possible to receive other errors in place of 503.
