App Engine Documentation PHP Standard Environment Documentation API Documentation \google\appengine\runtime\RPCFailedError Thrown by APIProxy calls when the RPC to the application server fails. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated February 22, 2017.