Hi
As replied, you will need to check in two places to make sure you don't select any terms and conditions article:
1. Go to Membership Pro -> Configuration, look at Terms and conditions article config option, make sure you don't select any article
2. Go to Membership Pro -> Plans, edit the plan, make sure you don't select any article for Terms and Conditions property of the plan
After that, the error will be gone
Tuan
