Launcher says "No Connection" when I am totally online.

When I try to log in to the launcher, this message shows "Sorry! Make sure that you are online and try again." I am definitely online. I have tried many different things including restarting, deleting and reinstalling, resetting network preferences, VPNs, third party launchers, and MANY wifi networks. Mojang PLEASE fix this, as I cannot even play singleplayer. It is completely impossible for me to play.