Unable to checkout using this plugin

This plugin used to work perfectly, something recently changed and I’m now unable to checkout using this plugin. only thing that changed was other plugins being updated to the latest. I have this plugin on 2 separate sites and both are not working as of last woocommerce update. http://www.misthub.com and http://www.ishopgear.com

http://wordpress.org/plugins/bitcoin-payments-for-woocommerce/