In version 2.0 and later, you will have to verify your email. This is a way for us to prevent spam.

When you sign up for the first time you will get an email with a verification link. Just click it and your email address will be verified.

If you already had an account you will need to go to the license settings and click on the "Verify now" button.

A verification email will be sent to the Account email address. 

If you do not get the email, please check your spam folder.

In the mail, click the link to verify your email then restart the program.