HDR Image not showing up

Hello everyone, I’m in the middle of a tutorial on the lighting part and when I try to put an HDR image thats what happens:

Should be like this when a locate the image:
http://postimg.org/image/5pw8ff9jd/
and like this when I preview the image:
http://postimg.org/image/r3uc0z757/

but thats what happens when I locate the image:
http://postimg.org/image/cp8lpqcmf/
and when I preview the image:
http://postimg.org/image/jdg2sv7rd/

So when I render, the background that should be a forest becames totally gray or black!

Please anyone save me?
Thanks a lot!

How have you mapped the texture to the world ?
Can you supply a blend file with the texture packed in it

Problem solved, the file was corrupted and not opening correctly…
thanks anyway Richard