Make sure you're on the Internet tab and the filters are reset, try restarting the game. If you still don't get anything, restart your router. Also make sure 3rd party firewalls aren't blocking Pluto.
@nico13 try:
if you downloaded the game via the torrent and still have it loaded in your torrent client remove it (right click -> delete).
redownload the launcher from here and run it as admin https://cdn.plutonium.pw/updater/plutonium.exe.
change your dns servers (https://www.windowscentral.com/how-change-your-pcs-dns-settings-windows-10)