Import .ova in Parallels

Hi, I'm trying to import an ova file in Parallels. Seeking in the forum I found 2 ways to do it but none of them works for me.

1. First one with: https://kb.parallels.com/122835 (is with ovftool )
2. Second one: https://www.parallels.com/blogs/convert-virtualbox-to-parallels-desktop/

When import the file (.vmx with the first example or .vbox with the second example) Parallels says 'This VM don't have installed any operation system':



What am I doing wrong?
Thanks