You may see this error when opening Rhino6 or later. You get these errors when the McNeel license server can not be reached.

“This site can't be reached.”

“McNeel servers can not be reached”

Rhino must be able to connect to the following websites though port 433.

• https://accounts.rhino3d.com (port 443)
• https://api.mcneel.com (port 443)
• https://cloudzoo.rhino3d.com (port 443)

• You could try disabling the firewall to see if that changes anything.
• You may need to consult your computer for specific steps for to allow access through any network firewalls and/or anti-virus applications you have running.
• If you have an IT department at your school or company, check with them and share the links I provided above.
• See Forum thread with more ideas https://discourse.mcneel.com/t/mcneels-license-server-could-not-be-reached/87744:here.
• Alternatively, a tool like https://www.testports.com/ should be able to test the connection for you.

More Help Email the following to Rhino tech support tech@mcneel.com

• Rhino System Info: Open Rhino and type the command SystemInfo. Copy can paste the text results into your email.
• Send a screen capture of you error
• On Windows, send the hosts file located in C:\Windows\System32\drivers\etc