No matter what number it is, the license key must be valid for the full set of active users on the domain you are purchasing license to (that we can verify), as certificate The certificate MUST be set to a serial number unique to the domain and for the number of users on the domain. What serial number is unique? The serial number, or UUID, is a value in Base-64 format generated by the PDF Samba Client and used as a part of the client's identification to identify the software. How does the software identify the number of users? The serial number (or UUID) must be unique across all of its server nodes. We offer a unique UUID as part of the PDFs Visual installation on all volumes and on the download and installation pages. The UUID is used to identify the application. It cannot be changed or changed after it has been activated and the installation completes. The UUID must always identify PDFs Visual and must be valid when the installation is finished. What is the UUID for PDFs Visual Version 4.0.1? Version 4.0.1 serial number is XAACD-9CD0-A9F1-BC9D-5E7DBAD1C6F9 Why are you offering to purchase this for us? We can make use out the value of the serial number in the Sea Client to provide a simple license key for our customers who have already purchased a trial of PDFs Visual. The trial activation must have expired before you can activate for a full lifetime license. If you fail to activate the version activated on your behalf within the activation time period, the license on your machine will be cancelled and the license key will be cancelled. What do I do if I do not activate after two weeks? Please contact us at and the issue will be handled as appropriate. What happens if I can not activate the product? You still have the original serial number for the original installation of the software Can I use the activation on 2nd generation (4.0) machines and later? You can activate this version with previous install, it is the same software.