Some users may receive a key through a bundled subscription service.
The bottom line is simple:
The activation key has already been applied to another computer or hardware device. Vector keys are generally single-use unless specified as a concurrent multi-seat license.
If you have a valid activation key from your purchase or license administrator, follow these steps to activate your software: Open the Vector License Client
Search your email inbox for the email address used during purchase. Look for keywords such as: "Vector Canoe Order Confirmation" "License Information" "Thank you for purchasing Vector Canoe"