The password for LeagueSecretary.com is now CAse SEnsITive. So most likely the issue is due to entering a password that does not match the letters and how they are UPPER or lower case. If needed, go to LeagueSecretary.com, log in, then change your password, noting the UPPER/lower case of your new password. Then come back to BLS and enter the new password.
You may also want to clear out the league ID, Username and Password and re-enter the information in again, double-checking the password.