FileZilla Forums

I've set up an IIS 10 FTP server requiring explicit TLS/SSL (an FTPS server). It is only seen by users on the internal network, with access controlled by Active Directory, so there is no firewall involved. I am using FileZilla 3.60.2 to connect to the server, with the intent of making FileZilla the primary user interface to a NAS for about 100 internal users.

FileZilla connects without issues, lets me see the top level of folders in the virtual directory, but only allows me to browse folders below the virtual directory's root for a few seconds, if at all, before starting to give me a "550 The system cannot find the path specified" and "Error: Failed to retrieve directory listing." I have no issue browsing the ftp root on the server's physical drive, but not these virtual directories, which are connected via UNC paths to the NAS. The server stays connected throughout.

I have double-checked the permissions, which are consistent from the FTP site all the way down -- "modify" permissions are granted.

I have tried this with WinSCP and have no problems. I'm reluctant to move away from FileZilla, however, as a lot of people here already use it. I just can't see any differences between the setup of the two of them.

The Internet has not been helpful so far. Any clues about how I can troubleshoot this?

Please post complete a log showing this.

Here is a recent session debug-level log. I've obscured a few details for privacy.

The server is using Unix-style directory path format in PWD responses. It seems you have selected a different server type in the Site Manager.

Thanks for the reply.

I have tried several server types. Some give me an error: "Default remote path cannot be parsed. Make sure it is a valid absolute path for the selected server type." I'm not sure exactly what that means. Server types that give me that error are Default (autodetect), Unix, DOS-like with virtual paths, and Cygwin. Server types that DON'T give me the error are DOS with backslash separators and DOS with forward-slash separators. The other server choices seem like unlikely choices for an IIS server.

On the IIS server I've tried these choices with the ftp directory browsing settings both for MS-DOS and Unix.

One odd thing is that, at random times, I can connect and enter ONE subfolder, then as if the server realizes it doesn't like my settings, stops letting me in anywhere else. This is completely inconsistent; most of the time it doesn't let me in to the subfolder, but when it does it's always just the first folder I click on.

Have you tried switching to a better, more well-behaved server software? Basically anything that isn't IIS.

Not a helpful answer for my situation, but probably a correct one nonetheless! I hear you have a server product as well...

Whichever server you decide to use, make sure it supports TVFS and MLSD as defined in RFC 3659 to avoid all issues switching directories, parsing PWD replies and parsing directory listings.