@Victoria In the dashboard, go to Settings->Permalinks. Click on ‘Save Changes’ and see if this solves the issue. Also make sure there is a page with id ’20’.
Thanks for your response Sanjip. It turns out there is no page with an id of “20”, despite the error link. (The page where I want my posts to show has the permalink: http://www.proconciliation.com/?page_id=183.) I don’t know how to reconcile. Further help would be appreciated. Thanks!
Nevermind. I figured it out; I had to permanently delete the other pages I had previously created for the same purpose. Once they were gone it fixed the problem. Thanks for your help.