To update your mathcad license and point it at the proper server, follow the instructions below:
1) Open up a file explorer window, and navigate to: C:\Program Files (x86)\Mathcad\Mathcad 15\mclicense
2) Inside of this folder, there should be an executable: mclicense.exe. Open this application.
3) The application should look like the following picture. Select "I want to configure Mathcad to use a flexLM server" and then hit next.
4. You will be prompted with two options.
Select the option "use a license server". The server name needs to be replaced with: "flex1.cose.isu.edu;firstname.lastname@example.org;email@example.com"
and the server port is: 27011.
Once that is done, you should be able to to press next and then finish. Your screen right before you press finish should look like the following: