Starting July 10, 2018, a new Salesforce Notification Banner appears to admins working in Salesforce Classic. The banner encourages admins to start thinking about their org’s transition to Lightning Experience by visiting the Lightning Experience Migration Assistant and running the Lightning Experience Readiness Check.
If you’re already working on your org’s transition and don’t need this little reminder, you can dismiss the banner from a specific page, or disable it for your entire org.
To learn more about the banner, see “New Banner Encourages Admins to Transition to Lightning Experience” in the Salesforce Summer ‘18 Release Notes (https://sfdc.co/S4Sel).
