Hello,Kawayi.Welcome here.
When you are entering the serial number, please note that it is easy to confuse the letter "O"(letter O) with "0"(zero) and "I"(letter I) with "1"(one). All the letters in the number should be capitalized and the dash can not be missed.So it is strongly recommended to copy and paste the serial number directly into the registration blank to avoid a manual mistake.
Or you can alsoretrieve your purchase information and get your serial number by yourself with your order email or order number at web
http://www.cheesesoft.com/support/customer-area/member-login/