it looks like an Apache configuration error - ie the information held by server as to actual location of the web pages in the host's file system is incorrect (note this is not the same location as the URL) - usually because someone has altered the file system or renamed some file.
Might I suggest you set up a local image of the microsite (eg under a local offline version of Apache which is free + readily setup up on any simple laptop) then you can check out links (+ remove all those totally unneecessary javascript links that fouled up the transfer) update with Ian's section , then move the entire + updated site to the online server into its new home.