Command Center accounts can only be accessed if you had signed up prior to 2017. It caters mostly to legacy products like Z3TA+2, Sonar Platinum, etc. New registrations have long been closed. I believe you're referring to our Product Center, which handles CbB the new Sonar and Next products and can be accessed here
The product center specifically handles app updates related to CbB, Sonar, and Next. You can learn more about it here - https://discuss.cakewalk.com/topic/69413-cakewalk-product-center-version-100051/
If there are any concerns, please drop us a line at support@cakewalk.com.