private Optional<ConsoleCommandSender> get() {
        //noinspection ConstantConditions
        return Optional.ofNullable(this.server.getConsoleSender());
    }
The {@link Server#getConsoleSender()} method returns null during onEnable
in older CraftBukkit builds. This prevents LuckPerms from loading correctly.
bukkit/src/main/java/me/lucko/luckperms/bukkit/util/NullSafeConsoleCommandSender.java