Every effort has been made to ensure a smooth upgrade process but please make sure you backup your database before installing anyway.
IMPORTANT:
Upon activation of the plugin a CSV file will be emailed to the Wordpress admin email address containing all orders up to that point in time. This is to collect previous orders and record them so that they won't be sent again and risk causing repeat orders. In addition to this precaution, I also advise you to always include the 'edited' field in reports so that there is always a date associated with each order. The edited field is only updated when the order is changed in some way, so your fulfillment center/s should notice if orders from months or years ago are being received. If you're expecially concerned, you could even give the column a custom heading to draw attention to it.