MySQL Error reading packet from server: Binary log is not open ( server_errno=1236)

my.cnf

[mysqld]
server-id = 20
auto_increment_offset = 2
auto_increment_increment = 10
master-host = 192.168.9.233 # node A
master-user = root
master-password = mypassword
log-bin=mysql-bin # I solved this problem adding this line