I got a message saying that my key was used on another computer. What should I do ?

This message tell us that your licence key is already used on another computer.
To used it on your current computer, you need to unlink your key from your previous computer.

Unlink your key

To do that, go on your client area.

Select the key you want to unlink and click on the Dissociate button.

Use your key on another computer

Then, you can use your licence key on another computer.