When you see that message it actually means that the registration info you had has expired and it either needs repurchasing or re-activation. Technically, the developers of the CDMS have the power to issue a new serial number to activate the software. You will have to contact them in order to obtain that data to re-activate the software. Unfortunately, I couldn't find any website related to the CDMS, but if you have the software, go to Help > Contact or Help > About. Use that info to get in touch with developers or with their website.