Unable to download/activate plugins

Hi there,

I bought a new theme but I am unable to donwload and activate the following plugins, any thoughts?

Vision Core
WPBakery Page Builder
Layer Slider
Revolution Slider

The error is: "Downloading installation package from http://theme.vision/updates/?action=...1bfa0fa36ca3c…

Download failed. Forbidden"

Try to activate the server to server connections ("Setting"->"Server To Server").

Bye!