No action responded to data error using link_to .download a file from specific location

Hi ,

I have appliaction which has various type of streams.
And iam providing a link to stremname .
ex:suppose i have stream called test.mpeg4 in public/data/test.mpeg4
using to link to stream.
<%= link_to, stream.location %>

in index page of controller if i click on name of stream it is
pointing to below link and able to download.

if i use the same link in show page it is pointing to below link

and as a result not able to download stream anddisplaying like
Unknown action
No action responded to data. Actions: create, creates, destroy, edit,
index, new, show, test, and update

can any one suggest how to resolve the problem.