Fatal Error after updating Chat Plugin

After updating the Chat plugin, I got a fatal error;
Fatal error: Call to undefined method BP_Group_Extension::init() in flippedclassroom.ca/wp-content/plugins/wordpress-chat/lib/buddypress/wpmudec_chat_buddypress_group_1.8.php on line 55

I've had to delete it from ftp to get my site working again. I would love to get this plugin working again. Did I do something wrong?
I updated from the wpmuDev dashboard.