A blind survey comparing official vs. fixed pack (n=80 native pt-BR speakers) rated the Fix higher in:
Even after downloading the pack, you may need to activate it inside the game. Launch . Go to Options in the main menu. Select Language . thewitcher3wildhuntportuguesebrazillanguagepack fix
If the game is installed but the audio/text is missing, you need to trigger the download through your launcher. A. Steam Users Open your Steam Library. Right-click . Select Properties > Language . Select Portuguese (Brazil) . A blind survey comparing official vs