Summary: How to fix the installation Error 1939.
Related installation help: Troubleshooting Rhino 5 Installation
I get Error 1939 'Invalid command line argument'.
One common cause for this error with the Rhino 5 installer is the use of extra double-quotes (“) when entering user information during the setup.
When you enter your name and other user information, do not type any double quotes, for example typing something like:
Bob “Grumpy” Ross
as a user name would cause this error.