tags archive is showing 404 error

There are tags associated with the posts. On the index I do not display them. On this page: http://www.unitedwithlove.com/vendor-guide/hair-and-make-up/ you can see under the image in the featured section a link that says “See More”. This is a link to a tag associated with all posted from this vendor. It should use the archive page but instead is kicking to a 404. As far as I can tell the link is generating correctly.

Are there any reasons for this to be occurring?

EDIT: Apparently it has fixed itself. The 404 errors seem to be a part of a larger problem with timouts maybe? The site is hosted on a shared server with another blog and both receive a ton of traffic. Hopefully getting them to a VPS will solve the random 404’s as both sites experience this.