Sample Data Install

Hi,
I installed a free theme to my WordPress but i have a problem for installing sample data. I followed the instructions here http://www.crocoblock.com/documentation-ecommerce/jigoshop/index.html
but when i uploaded the .XML and .JSON files it doesn’t work and i get this message : Fichier .XML ou .JSON manquant while the files are uploaded ! Could you help me please ?