facebook/facebook-ios-sdk — pull request #525 by monicataina (2013-04-04 07:47:34+00:00)
Title: Update FBAccessTokenData.m

Operator [] for a dictionary isn't implemented on firmware less than 6 and a crash can occur. Please check the following bugs: https://developers.facebook.com/bugs/346207278814744 and https://developers.facebook.com/bugs/230266263783283