Check if you have "Players" selected in Enemies. Also check if you have AntiBot misconfigured and enabled. Or Teams enabled and misconfigured. Or Focus enabled?
@ĐạtTv-Gaming you can try to download with vpn, or go to %appdata% and .liquidlauncher (I don't remember what the folder is called from the launcher), then remove liquidbounce nextgen and try to download it again