Matlab User licenses have been renewed. Now that the license has been renewed, existing users should be prompted to reactivate when they log-in to MATLAB for the first time since the renewal.
If you are currently using your license, you can update it by doing this:
Open up Matlab, then Help->Licensing->Update Current License.
After 7/31/17, you will need to re-activate your license, just as you did when you first installed the program, with the activation key you received.
If the license file has expired, existing MATLAB users simply need to launch MATLAB and it will start the Activation Client. Once in the activation client, users are provided with a guided workflow to re-activate the license.