sharepoint 2013,RSS viewer web part error

In SharePoint 2013,i added the web part for RSS viewer in my homepage in my development server and gave the link encountered an error “An unexpected error occurred processing your request, check the logs and correct the problem.

I checked the logs at C:\Program Files\Common Files\Microsoft shared\Web Server Extensions\LOGS with the ULS viewer. didnot understood the advise me how to resolve.