I've used this plugin quite a bit on WordPress 3.7-3.8.x.
On a 3.9 site right now, and after I enabled some social media related stuff in Yoast like Facebook Open Graph and Twitter stuff, and then disabled it, the site home page has a redirect loop. Updating permalinks doesn't help the problem.
If I disable the plugin, problem gone. I deleted and reinstalled the plugin. Enabled...same issue.