I have been trying to get a license file for 3 days now, and PTC's support website is garbage. I can't get help let alone a simple response. I've also tried calling our PTC/Mathcad rep, and he won't answer his phone or call me back. We have an engineer that has been unable to work for 3 days now because PTC doesn't seem to have any customer service or tech support staff. This is ridiculous.
This page should serve as a one-stop for Mathcad install and licensing questions: https://support.ptc.com/support/mathcad_supportCenter.htm#
Are you able to access, and do the steps there get you up and running ?
"License Management" section on PTC's site: https://support.ptc.com/apps/licensePortal/auth/ssl/index