403. That’s an error.

Your client does not have permission to get URL /api/manifest/dash/initcwndbps/2535000/ip/75.156.34.16/key/yt6/pl/22/signature/E3E2AFBCB35999C9D1788993CDF29E0FD55781E5.124529789FEAAF280CA95810622C4AD1EE58508B/itag/0/id/5a28c62363cdd4fd/requiressl/yes/playback_host/r8---sn-uxa0n-t8gz.googlevideo.com/mn/sn-uxa0n-t8gz/hfr/1/sparams/as%2Cei%2Chfr%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Cmm%2Cmn%2Cms%2Cmv%2Cpcm2cms%2Cpl%2Cplayback_host%2Crequiressl%2Csource%2Cexpire/ipbits/0/mv/m/mt/1501658415/mm/31/ms/au/ei/f32BWeSyE_DQ_AOEtICABQ/as/fmp4_audio_clear%2Cfmp4_sd_hd_clear/pcm2cms/yes/expire/1501680095/source/youtube from this server. That’s all we know.