Blogs not working?

[pjkcards]

When I enable the blogs, and click on the link in the nav tab, I get this error:

Database error in vBulletin 4.2.1:

Invalid SQL:

				SELECT tagcontent.tagid, tag.tagtext, COUNT(*) AS searchcount
				FROM tagcontent AS tagcontent
				INNER JOIN tag AS tag ON (tagcontent.tagid = tag.tagid)
				INNER JOIN blog AS blog ON (tagcontent.contenttypeid =  AND tagcontent.contentid = blog.blogid)
				INNER JOIN blog_user AS blog_user ON (blog.userid = blog_user.bloguserid)
				
				WHERE blog.dateline <= 1382953196 AND blog.pending = 0 AND blog.state = 'visible' AND ~blog.options & 8
				AND tagcontent.dateline > 1351417196
				GROUP BY tagcontent.tagid, tag.tagtext
				ORDER BY searchcount DESC
				LIMIT 70;

What is the best way to troubleshoot?
Thanks.