У вашего броузера проблема в совместимости с HTML5
In today's lesson, you will learn how to delete a Dropbox account.
Open a web browser. Go to a Dropbox web page and log into your account. Click on the account icon at the top right corner of the window. Select 'Settings' from the list. Scroll down and click on 'Delete account'. Enter your password. Choose a reason for leaving. Click on 'Permanently delete'.