Hello
There are some incompatible issues in Joomla 3.6.0 and 3.7.0 API, and we had to release new version to address it. Please purchase latest version 2.9.0, upgrade it to your site. After that, everything will work as expected (Your order was from 2015, so it was expired and that's why you need to re-purchase to get latest version)
Regards,
Tuan