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] 8U2TAXoUNI0: nsig extraction failed: Some formats may be missing
         n = 9xzeC5t51bXW_iY3N ; 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] 8U2TAXoUNI0: nsig extraction failed: Some formats may be missing
         n = rowHZ4Imu12Vtjydh ; player = https://www.youtube.com/s/player/e7567ecf/player_ias.vflset/en_US/base.js