Paypal is making changes to make their payment transactions to improve security. These apply to anyone using Paypal Standard, Paypal Express, Paypal Pro, or Paypal Payflow. 

We recommend that if you're using Paypal Standard that you switch to Paypal Express. We've had several clients report Paypal orders not getting recorded in the CFWebstore admin. This appears to a communications problem with Paypal Standard.

If you're using CFWebstore version 6.50 or above, Paypal Express is already built-in. It's simply a matter of setting up APi credentials in your Paypal account and adding them to payment settings in the CFWebstore admin.