Hi,
Have you tried to restart your computer and run the installer again?
It might be a temporary issue. How fast is your internet connection?
If you want more help from Laminar Research, you should include the installer log.txt written after attempting to update. you will find it on your desktop.
All the best with that,
Guillaume AMELINE
PS : I am not affiliated with Laminar Research
PS : you should choose more tags and make them more precise, so that you can be pointed towards related topics and so that your question can be as useful as possible for others in the future.