On the same version here and I just went there and signed out then signed back in no problem. Do you have any adblockers or anything like that running? Might try deleting the Youtube cookies and retry.
Same problem here. Can't 'sign in' to youtube on safari. Works fine on Chrome. I've disabled any adblockers and emptied cache (all of it!) but still can't log in.
Same problem here. Can't 'sign in' to youtube on safari. Works fine on Chrome. I've disabled any adblockers and emptied cache (all of it!) but still can't log in.
I finally upgraded to Sierra and now I can use Youtube on Safari just fine. Don't know what the major differences are between Sierra and El Capitan that would resolve this issue but, seemingly, it has.
Any thoughts on why?