Feed Validator error shows Unregistered link relationship

I read (https://evepheso.wordpress.com/2008/09/19/my-little-discovery-of-the-day/) that I can view the number of subscribers to my blog by using Google Reader. When I attempt to use it, I get an error saying “The feed being requested cannot be found.” When I try using Feed Validator (https://www.feedvalidator.org/) and enter my URL https://whereschristmas.wordpress.com/ it tells me:

This feed is valid, but interoperability with the widest range of feed readers could be improved by implementing the following recommendations.

?line 28, column 157: Unregistered link relationship: search [help]

… xml” title=”Where’s Christmas?” /> ^

I’m guessing the “‘” in my blog’s title is causing the trouble, but I don’t know what to do about it.

Does anyone know what I need to do to fix this?

Thank you ??

Todd