403. That’s an error.
Your client does not have permission to get URL /videoplayback/id/1b04daf0a17862a1/itag/18/source/gfp_video_ads/requiressl/yes/acao/yes/mime/video%2Fmp4/ip/0.0.0.0/ipbits/0/expire/1528424552/sparams/ip,ipbits,expire,id,itag,source,requiressl,acao,mime/signature/1C0F1792B30C7BF25E1DD3792E6B1BDAAB52ADE3.297F050A54050DCC764ECE8EA636E71DBC886E54/key/ck2/file/file.mp4
from this server. That’s all we know.