Most login issues are related to the wrong password being entered. If you forgot your password, click Forgot password? at the bottom of the login window and enter your email address to receive a password reset email for that account.
It can take a few minutes for the email to appear in your inbox.
Before submitting the form a second time, try searching your inbox for "firstname.lastname@example.org" and check your spam folder.
Note for GMail Users: Check your Social inbox rather than your Primary inbox. Emails from Livestream tend to be filtered there automatically.
The email looks like this:
After clicking Set New Password, you will be redirected to a new page where you will be able to enter a new password.
Once you click Save Changes, your password will reset and you will be logged into your account.
Did you not receive an email? Try whitelisting email@example.com in your email settings. Each email client will do this differently.
Please see here for a complete guide to whitelisting email addresses. (Note: you will be redirected to a third-party website.)