You get the message "Your K9 license has already been installed on a different machine."
Each K9 license is only good for one installation. If you want to install K9 on a second computer, you will need to obtain an additional license.
If you wish to move the K9 application to a new computer, you will first need to uninstall K9 from the old computer while connected to the Internet. It is important that you have an Internet connection when you uninstall K9 so the license can be freed. After the license has been freed, you can install K9 on the new computer using the same license key.