It is quite unnerving to suggest registry editing as a work-around. This should not be recommended. As such, and rather than disable any security software on my machine (Win10), once I understood that it was a font installation issue, and where the fonts were being stored, I was able to resolve the issue.

The following is a safer way to complete the installation. 1) After running the installation as administrator (which is successful), the program forces the user to quit. 2) Then going to the folder “C:\Program Files\Wolfram Research\Wolfram CDF Player\11.0\SystemFiles\Fonts\TrueType” where the fonts are stored after installation, I installed the fonts with administrator privileges, in batch (select all, right click, run as admin). 3) Open the program, no error should occur.

Check opening the program after manually installing the fonts in batch. I suspect that this may be the only required step after the initial installation.

To check this, I uninstalled the fonts, attempted to open the program, received the error, reinstalled the fonts and reopened the program. The program opened without error.

I hope this is helpful.

In my contact with TS, they offered three possible solutions:

1) checking to make sure any security software is not blocking external fonts- i.e. allow security exceptions for external fonts

2) turning off my firewall to see if this is the cause- then if it is allowing an exception for CDF Player

3) editing the registry.

I cannot make these security changes or registry changes on the system I am using. Font installation however can be done after an antivirus scan. After I installed the fonts, I sent a response to TS stating my solution and was given no warning by them that this could or would interfere with future versions. So I'm not sure why you would think this is the case. Even so, it's just as easy to remove the fonts if the developers fix this for a later version. But I doubt that would be necessary.

Yes, after doing the "Mitigations" registry fix to unblock untrusted fonts, I was still getting the same Error Code: 702 in the screenshot. So I removed this registry fix.

What I finally found was causing my issue was that the Windows firewall service was turned to "manual" on this computer. So all that was necessary was to run services.msc and set the windows firewall service to "Automatic" and Mathematica runs just fine now.