After messing around with my permalinks settings, all links began returning “404” errors, even when viewed from “manage>posts” section of wp-admin control panel.
The goal in my case was to remove the default positioning of “category/” from the url, but maintain permalinks as domain/%category%/%postname%/.
Tips said to visit wp-includes/rewrite.php and remove the “category/” from category_base.
Links worked for a short period of time, but randomly resorted to all 404’s. Now erasing .htaccess, or resetting permalinks to anything other than off doesn’t fix anything.