FTP Error help please

On uploading my site updates this morning I am getting the error message [ The Remote Folder /htdocs// does not exist. Do you want to create it?] in the error window is a Create Directory button and a Cancel. I tried the create directory but it didn't seem to do anything, just re-showed the error window.

I'm hesitant to mess around too much because the site is live at the moment and I'd like it to stay that way.SM:HELP

Have been uploading pretty much problem free for a year or more and it was OK yesterday.

Any idea's out there?