You are not able to use the webcam service if you meet one of the following conditions:
If you entered this information incorrectly, our system might show you as younger than you really are. It is not possible to update or change your birth date in our system for account security reasons.
If you entered your age incorrectly when you opened your account with Yahoo!, you will need to open a new account with your correct age. We apologize for any inconvenience this might have caused you.
If you are using Yahoo! Messenger and a HTTP connection or you are sure that the birth date associated with your Yahoo! ID indicates that you are over the age of 18, make sure you are using the "No proxies" connection setting.
To select this setting:
Close Yahoo! Messenger completely and start the program again. This should eliminate this error message.