Hi Mike,
I couldn’t reproduce the error here.
It’s odd that you have experienced the error Class WP_Background_Process not found, as that class is bundled on WooCommerce itself.
Anyway, I’m now checking for it and I’m loading it from WooCommerce in case it’s not found again.
Please, update the plugin to version 2.6.8 I just released. It should be ok from now on. Let me know if you notice something.
