membership 2 pro

I needed to upgrade to membership 2 pro but after installing what I believe was to be membership 2 pro from the WPMY DEV dashboard on my wordpress account I still have the same plug in that I had.

I also have these two issues:

1. I was trying to reset the plug in and kept on receiving this error- Fatal error: Class ‘MS_Addon_Coupon_Model’ not found in /home/weekly50/public_html/wp-content/plugins/membership/app/model/class-ms-model-upgrade.php on line 506

2. I dont know wherther its what I did but now when I try to access membership list page on the website it seems the signup button for doesnt appear just the membership information only that appears.

Urgent help would be appreciated