If you do not have an installation ID then you have installed the software without Administrator permissions. You need to be logged on to your computer as an Administrator in order to install iC3D as the installation ID is taken from the MAC code of your machine.
On a macintosh computer you may have to be logged on as a ROOT Administrator to be able to access the MAC code. Apple Support provides information on how to set up your computer as ROOT Administrator or you should contact your IT support.