The file you are attempting to save or retrieve has been blocked from this Web site by the server administrators.

Have receive this error couple of times while working with share point web services ,


"The file you are attempting to save or retrieve has been blocked from this Web site by the server administrators."

Outsource the incorrect URL caused this , however the description of the error makes it confusing 

Correct URL should be http://web.domain.com/sites/sitename/_vti_bin/lists.asmx

URL by error occurred http://collaborate.kronos.com/sites/datadump/vti_bin/lists.asmx - notice missing "_ "  here