Error upon start up "Failed to load module script"

[ZouZou]

I have downloaded the latest version on my window 10 64 bit machine
Unzipped and clicked on Hass.cmd
The browser opened up and I could only see the HA logo, went to the dev tools and found the following errors

Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/plain". Strict MIME type checking is enforced for module scripts per HTML spec. onboarding.9b8c4e99.js:1

Uncaught (in promise) TypeError: Failed to fetch dynamically imported module: http://127.0.0.1:8123/frontend_latest/onboarding.9b8c4e99.js onboarding.html:1

Any idea what could be the problem?