This issue has brought down our production site AGAIN. All browsers.
Original thread (since closed) here:
Uncaught TypeError: Object OSummary has no method "getelementsbyclassname"
Source of Error: "http://s7.addthis.com/static/r07/core004.js"
I can't link you to our site to show you the issue because we have decided to permanently remove AddThis from our website due to this happening a SECOND time. I'm sorry to say but epic fail on your Engineering & QA team.
"Fool me once..."