The license number/serial number is based on the Notes user name or on the fully qualified Notes user name (File | Tools | User ID | Name) that you provided during registration. If you did not provide the correct name during registration, you will get a "License not valid..." error message during installation. In such case, you will have to enter the exact error message in the online Pylon License Questions form and a valid license will be issued.
If the error message refers you to Globalware instead of iAnywhere, the license (serial) number you have is probably correct but you are trying to use it with an old Pylon Conduit version (e.g., 3.0, 4.02). Enter the exact error message in the online Pylon License Questions form and the correct download link will be issued.