WARNING: [youtube] Falling back to generic n function search
         player = https://www.youtube.com/s/player/0f7c1eff/player_ias.vflset/en_US/base.js
WARNING: [youtube] GYdgFLc6WOE: nsig extraction failed: Some formats may be missing
         n = ke-Y0DE_tDk0yoDxG-b ; player = https://www.youtube.com/s/player/0f7c1eff/player_ias.vflset/en_US/base.js
WARNING: [youtube] Falling back to generic n function search
         player = https://www.youtube.com/s/player/0f7c1eff/player_ias.vflset/en_US/base.js
WARNING: [youtube] GYdgFLc6WOE: nsig extraction failed: Some formats may be missing
         n = FrMzBFW-nBex-0KGqzY ; player = https://www.youtube.com/s/player/0f7c1eff/player_ias.vflset/en_US/base.js