If you are running into ERR_NAME_NOT_RESOLVED when accessing a Local site in your browser, odds are the hosts file on your device isn’t properly updating.
Bitdefender
Once common offender for this problem is Bitdefender. By default, Bitdefender will disabled “untrusted” changes in the hosts file periodically by commenting them out. Here’s how you can go about disabling that functionality in Bitdefender.
Screenshot Credit: @maximejobin