This issue has been resolved. The problem was not Ubuntu 16.04. For some bizarre reason I received the wrong license file contents. When using my institutional email on the freesurfer website registration form I receive this file:
The information in this e-mail is intended only for the person to whom it is
addressed. If you believe this e-mail was sent to you in error and the e-mail
contains patient information, please contact the Partners Compliance HelpLine at
http://www.partners.org/complianceline . If the e-mail was sent to you in error
but does not contain patient information, please contact the sender and properly
dispose of the e-mail.
Which is not the contents of the license file. However, when I put in my gmail email address on the registration form I receive an email with the correct license file.