"The seller accepts encrypted website payments only. You cannot pay the seller through un-encrypted buttons. Please contact your seller for more details."
This error may show if you're using PayPal Payments Standard and changed a setting in your PayPal account to require encrypted buttons. Requiring encrypted buttons will make the dynamic buttons which Acuity requires no longer work, since a new button is generated for every appointment.
This is different than your website encryption. Even with encrypted buttons disabled, your connection between you and Acuity (and between you and PayPal) is always encrypted and secure.
To enable un-encrypted dynamic buttons:
1. Log in to your PayPal account.
2. Click Profile.
3. Click My Selling Tools.
4. Under Selling online, locate Website Preferences and click Update.
5. In the Encrypted Website Payments section, select Off.
6. Click Save.