There are two things that can cause an Invalid License error in Boardmaker Studio.
The first happens when attempting to register and it is not accepting your Product ID. When entering the code double check to make sure there are no typos. A common mistype is switch the LC to CL in the first block of numbers.
The second issue is getting the error before even getting to the registration screen or if it has been working fine and now isn't. This is cause by a corruption of the locally stored license file. If this happen please go to the following location on your computer and delete the file called boardmaker.LIC and then try Studio again.