Hi Erica,
Yes, that is the conflict, the site is looking for this URL (http://ericacorder.com/portfolio/portraits
) as if a portfolio post because of the slug /portfolio/
, but it cannot find it so it returns 404.
That portraits
page got the slug portfolio because that is a child of the portfolio page.
Please follow Lely’s advise to change the portfolio
slug to portfolio-item
in X > Theme Options > Portfolio > Custom URL Slug
Or unset the portraits
page from being a child of the portfolio
page.
Note; after you do any of that changes please re-save your permalinks under Settings > Permalinks so it will re-index.
Hope this shed some lights,
Cheers!