On July 9th, 2015, Facebook tagged the latest stable version of the Facebook PHP SDK, version 5. This guide will help you upgrade from version 4.0 to version v5 of the official Facebook PHP SDK. Wait - what happened to version 4.1? Before the decision to adopt Semantic Versioning, the official Facebook PHP SDK was going to be released as v4.1. But now v4.1 is just an alias to v5.0.0. So any refere