Using the latest SilverStripe 2.4.5 and tried both the production and HEAD eventmanagement module, this error prevents accessing the detail view of a Registerable Event page.

[User Error] Uncaught Exception: Object->__call(): the method 'getstarttimestamp' does not exist on 'RegisterableDateTime'

It was suggested by someone on IRC that perhaps this function existed in an earlier version of the core, or a dependency, but no longer does. Would anyone have an idea what this function used to look like, or how to gracefully bypass this error?

SOLUTION: Download the latest EventCalendar module from github, as the production file linked from the website does not contain the required function.