when share a rails page on facebook (link you're sharing might be unsafe)

I have worked on ruby on rails platform.

When I try to share one page on facebook by facebook like & share button, there is a security check dialog tell me this message:

It looks like a link you're sharing might be unsafe. If you can, please remove this link:

http://***.com/media

Note: The unsafe link might be on the page you’re linking to.

If you can't remove this link and you still want to share it, please complete the security check below.

What's the link "/media" in rails? and how I can solve this issue?

Thanks.