It helps to know which client version you are trying to run. The only one that has missing files is the Underfoot client, so I assume that is the one you are running. If so, you should check this page:
http://www.eqemulator.net/wiki/wikka...ssingFilesList
Which is linked from the Play Guide:
http://www.eqemulator.org/wiki/wikka...akka=PlayGuide
EDIT: I combined your new thread with this one, because they are both the same issue even if they are different symptoms. I see you mention you are running the underfoot client, but did you get it from Steam? If so, I would suggest you delete it and download it again from Steam. It sounds like you have a corrupt install or something. Even though the Underfoot client is missing files, it is still very playable with just a few glitches even if none of the files are replaced. Your issue of not even being able to fully log in (etc) is not something that happens on a standard UF install from Steam. My guess is that you either accidentally patched to Live (even a little) or you installed Underfoot from an illegal download which could be broken in any number of ways and is not supported here.