More 404 errors with Portfolio links

When portfolio thumbnails are clicked, a 404 “nothing found here” error message appears… for almost all portfolio items.

The exceptions:
1. vimeo links, pasted directly into add media URL
2. a portfolio page that is only a URL text link

Portfolio items that 404:
1. youtube links pasted directly into add media URL
2. soundcloud links pasted directly into add media URL
3. links with link-embedded pictures for anything

What I have done:
1. tried to reset/re-save permalinks. hit save. changed to a couple different types and hit save. went back to the original and hit save.
2. checked htacess file, settings are as supposed to be (644)
3. removed all unused plugins

thanks

The page I need help with: [log in to see the link]