I am unable to access the admin areas of several sites on my multisite network, in addition to the network admin area. I am, however, able to access only one site (which is very strange). After logging into any of the admin areas, I am immediately taken to an Error 404 page, reading:
Error 404: This page was not found, page is missing or removed
This has been doing this for probably the past month or so. It happened out of nowhere; everything was fine before. I currently am running WordPress 3.5.1. I need help with this urgently. Any help is desperately needed.