There are several reasons why BBK Parental Management Verification Code failed to be sent.

1. Sending failed because the SMS signature is inconsistent with the submitted signature. Solution: Correct the SMS signature and resend it.

2. The verification code is invalid. Solution: Clear the data managed by parents, and then start counseling again.

3. The phone number entered by the user is incorrect. Solution: Check whether the phone number is correct and re-enter.