We have noticed many of the registration conflicts may be occuring because there is missing information in the SportsEngine profile you created for your child. Please ensure in the SportsEngine profile your child's Date of Birth and Gender fields are completed so they connect with the registration.
If you have created 2 profiles for your child by accident please merge their accounts. Follow this link: How to Merge Duplicate Profiles within MySE - SportsEngine Help Center
If you have two Sportsengine Households that need to be merged together follow this link: I Have Two SportsEngine Households That I Need Merged Together - SportsEngine Help Center
How to change Sign in Email: How to Change My Sign In/Primary Email Address - SportsEngine Help Center
How to update Sportsengine profile information: How to Update Profile Information - SportsEngine Help Center