WARNING: [youtube] Falling back to generic n function search
         player = https://www.youtube.com/s/player/e7567ecf/player_ias.vflset/en_US/base.js
WARNING: [youtube] TTYxTliD7W8: nsig extraction failed: Some formats may be missing
         n = 8cu8TR0RLhbVNA3mf ; player = https://www.youtube.com/s/player/e7567ecf/player_ias.vflset/en_US/base.js
WARNING: [youtube] Falling back to generic n function search
         player = https://www.youtube.com/s/player/e7567ecf/player_ias.vflset/en_US/base.js
WARNING: [youtube] TTYxTliD7W8: nsig extraction failed: Some formats may be missing
         n = wYSGNQ8no6vmkW4wy ; player = https://www.youtube.com/s/player/e7567ecf/player_ias.vflset/en_US/base.js