This "too many logins" error message is displayed because Moodle has detected that you, or somebody else, has tried to login to your Moodle account with invalid credentials too many times. As a security measure Moodle only allows a certain number of failed logins and will temporarily block any further attempts to login with the username that you were using.
Restart your web browser and, if you have your correct username and password, try again in 10-15 minutes. Alternatively, ask an administrator for help.
The parameter is hard coded in lib/moodlelib.php: $max_logins = 10;
- Notifications for login failure notification settings