import from windows 2008 to windows 2012

Hello;

I have a windows server 2008 R2 with 2 HPV servers, I have installed a new windows 2012 R2 std server, and would like to move the HPV from 2008 to the new 2012.

I have exported the HPV servers, but when I try to import, I get the error " Hyper-V did not find virtual machines to import from the location"

I am looking for a way to do this, there is a lot on the web, but non that have worked for me?

thx