App Engine Documentation PHP Standard Environment Documentation API Documentation \google\appengine\runtime\FeatureNotEnabledError Thrown by APIProxy when the app must enable a feature to use this call. 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.