Question : 550 and 501 errors FTPing

I am not FTP expert, so please assist.

We are using WS_FTP Pro to upload files to another organizations FTP site.  We use this same app on the same server to successfully upload to several other sites, but this one site keeps erroring.  So, I think it's either an access issue on the remote site server, or a configuration on our end.  Below is part of the log (private info changed) where the error  messages occur.  Any limited information I'm finding indicates we may not have proper access to the remote server directory to which we are uploading, but I need another opinion.

We are transferring text files in ASCII mode.  The remote site states if they get a file it is "empty".  Oddly enough we seem to be able to download files at times, but sometimes get these same errors when downloading as well.

This is part of the transfer log -
I get this block of errors:

   550-NAMEFMT set to 1.
   550-Specified directory does not exist or cannot be accessed.
   550 Working directory not changed.
   XCWD /CC
   550-Specified directory does not exist or cannot be accessed.
   550 Working directory not changed.
   CWD CC
   501 Unknown extension in database file name.
   XCWD CC
   501 Unknown extension in database file name.
   CWD CC/CC1
  501 Unknown extension in database file name.
  XCWD CC/CC1
  501 Unknown extension in database file name.

Then later in the log file I get this error:

  500  subcommand is only allowed for block or compressed modes.
  This server does not appear to support restarts.
   -- Resuming of interrupted transfers disabled.
   -- Multipart downloads disabled.
   Finished checking for "REST" command support.

Then later this error:

  501 File name must precede member name.
  Transfer request completed with status: Failed, 1 SubItem(s) failed
  Starting request

Answer : 550 and 501 errors FTPing

WS_FTP Pro is fairly simple to use, not a super GUI interface, but is pretty reliable.

Just set up a site like this --

Site Name -- anything
Site address -- ftp.thatsite.com   -- DO NOT use the ftp:// prefix here, it doesn't work
site login -- always a login -- no anonymous for another known site, it will limit what you can send
site PW -- always a PW  -- if not, the other site won't athenticate.
folder -- if this is a webserver, like a linux server, use -- public_ftp
If a private server, use the folder you want it to go into.

Once you have the parameters set, there is NOTHING that cannot be uploaded, unless --
1.  the file name includes illegal characters, like *&?
2.  The other site has restrictions on what can be uploaded.

Also, leave SW_FTP in the default port mode -- port 21 is the standard FTP port.

Check routers at BOTH ends, make sure they are not blocking port 21.  Also, if a DSL line, make sure that the DSL ISP (your phone company) is not blocking port 21 traffic on their network.