Undsgn - Preview Page Not Working

Envato Customers Purchases and Subscriptions
#1

The preview any of the changes I’m making to my website pages. I also cannot preview a post or portfolio page before posting this live.

Does anyone know how to help.

#2

https://blackmatterdesign.com.au/?preview_id=82699&preview_nonce=89fa1f3913&_thumbnail_id=78585&preview=true