Hi, you don’t need to reinstall the browser.
https://community.brave.com/t/how-do-i-enable-widevine-in-beta-when-the-browser-does-not-prompt/36739/4?u=mediabird
Try the offline installer, your firewall should not complain 
If the error is still displayed, restart your PC (so that Brave is terminated if necessary, it should still run in the background).
Have a nice day! 
2 Likes