*** Very important news *** PLEASE READ THE BLOG BELOW!

The Salesforce Winter ‘16 release is quickly approaching and soon you'll be able to take advantage of exciting new features and functionality! If you are a Sandbox customer, you have the opportunity to get early access to Winter ‘16 in your Sandbox and test new customizations and features before your production organization is upgraded.

The Sandbox Preview window for Winter ‘16 is scheduled to begin September 11, 2015. If you would like your Sandbox organization to take part in the Winter ‘16 Preview, your Sandbox must be active on a preview instance by September 11, 2015 to take part in an overall instance upgrade.

Salesforce Winter '16 Sandbox Preview Instructions