I'm a student so have got the AutoCad 2013 software for free. During the register section of the installation when I put my serial number and product key in, and then click continue this message comes up:
The Serial Number or Product Key don't Match. Valid format for serial number is (XXX-XXXXXXXX)'
In your case, this is being caused by a backend systems issue associated with the Education Community which has since been resolved.
The only workaround at the moment is to manually activate with an activation code. Please either send me a Private Message (click on my philip.s profile name and then "Send this user a private message") with your serial number and product request code, or contact our Registration and Activation team directly for additional assistance.