If you're using Linux Ubuntu / Debian with Java OpenJDK (Spigot, Craftbukkit, Forge, etc.) and having issues with Minecraft clients showing Mojang's "Authentication Servers Are Down", run the following command and restart Minecraft and the server.

update-ca-certificates -f
War diese Antwort hilfreich? 30 Benutzer fanden dies hilfreich (714 Stimmen)