Update iPhone SE

I'm trying to update my iPhone SE to the newest version (11.1.2). I always use iTunes to do this, never gone wrong. But now it did. He will say that he is busy, then stops and gives an error (14). On the website it's said that it has to do with my cable. But I tried other ones and it still doesn't work.

I only have my Macbook with iTunes on it and always used this computer to install.
I wanted to call Apple. But since I have no phone, it isn't possible. Can anyone help me?