Can't map network drive to FTP server in local VM

I've just set up an instance of Ubuntu Server 17.04 running in VMware Workstation 12 Player on my Windows 10 Home workstation. I got the server configured to my liking (including vsftpd as an FTP server, so that I can map a drive from the host) without any trouble.

Unfortunately, however, when I use the Map Network Drive wizard to connect to "ftp://192.168.154.128" (both with and without a trailing slash), I get an error — 0x80070043 — saying the "network name" cannot be found.

Running the troubleshooter by clicking Diagnose doesn't turn up anything, simply saying that the troubleshooter failed.

If I try to connect to the same address using the command-line FTP client, however, everything seems to work fine:

C:\Users\benblank>ftp 192.168.154.128
Connected to 192.168.154.128.
220 (vsFTPd 3.0.3)
200 Always in UTF8 mode.
User (192.168.154.128:(none)): benblank
331 Please specify the password.
Password:
230 Login successful.
ftp> pwd
257 "/home/benblank" is the current directory
ftp> quit
221 Goodbye.

Web searches for the error code haven't been very enlightening, primarily suggesting DNS or SMB problems, neither of which are involved, here.

Any ideas what might be going wrong?