If the DxO software you're activating says you have an invalid code, please make sure to omit the Nº before the key.
Some license keys are sent in this format:
Our software will not recognize the Nº symbol and say your key is invalid. Please omit the Nº symbol and enter only the remaining characters.
All license keys are 16 alphanumeric characters and can be copy/pasted into the activation screen.