First of all, I need the full file name of the file that is causing this. If you don't want to list the full path (because it contains the websites name), please just name the file and path from after the domain bit in the file path.
Most errors like this are caused by outdated plugins or themes, so please check all your plugins and themes for updates. If you are confident everything is up to date, you should confirm that all plugins and the theme you are using have received an update to be compatible with WooCommerce 2.0. This new version has changed a lot and we have been communicating with plugin and theme developers since December last year, still a lot of developers haven't updated their code yet, unfortunately.