I don't get the connection between calendar issue and that one in contacts. Understanding EPESI processing may be a clue here. When you do something in EPESI (click, navigate) your browser asks process.php file on server for the JS. That JS is evaluated in your browser. It's responsible for contents change and new javascripts. If JS retrieved from the server will cause error, then it'll stop processing retrieved JS. So everything after the error is not processed.
And what's the Unexpected identifier? error_libs_qf_72de4043a3abbbc2e292498bd8515641_zone_commondata?
PS. You've got really strange theme... Maybe your custom template causes some issue? 😉
