Receive an error 404 (Not found) while accessing an URL (for which 'Use system proxy' option is enabled) which is outside of the corporate network.
Receive java.io.exception in the logs while interacting with the push notification provider server such as APNS, GCM, or BIS exists in the network, although it shows 200 (OK) during push operation.
Above mentioned problems occur when the proxy settings are not configured in the server. Due to which, from corporate network, server fails to communicate with the outside network. You need to enter the proxy settings manually in Management Cockpit.