Photshop elements 15 bought in UK not working in South Africa

I [urchased a elements15 (CD) with 2 user license in the UK. I put 1copy on my UK computer OK. However, now in my second home (in South Africa) the software loads then requests the serial No. of the disc from the back of the paper disc cover. When I enter the serial No the sofware will not accept it, No where does Adobe's information say 2 copies allowes, but must be in the same country!