A few days ago i was still able to access Platinum 14, but today when i logged on, it told me to enter the serial number. It showed me Error-14 when i entered the exact same serial number it showed me on my mail for my platinum 14.
Please contact customer support either via https://support2.magix.com/customer/vegas or call the pre-sales line at 1-305-722-5810 between 12:00pm and 4:00pm CST. They should help you out.