My Core server activation succeeds but I am unable to login or use certain parts of the product. For example, maybe you can login to the core, but you are unable to get patch updates.
Verify that you have the needed licenses with the correct versions in your license details of your core. You will need to carefully scroll through the list to make sure that you have what is required. If you don't have what is required or have any questions then you should contact firstname.lastname@example.org to get your license squared away.