I cannot verify my site with google analytics code

Hi,
I’m getting crazy with google analytics code as I’ve followed all instructions written here
https://support.google.com/analytics/answer/1008080?hl=en

I paste the code just above the tag </head> in the header.php file, but when I’ll go to verify as owner my site google says to me that my code is in the bad position.
Someone can help me, please? I need it a lot beacause I can’t understand where is the mistake.
thank you very much