FTP: connection lost when initiating a new connection

[mag]

- server f.p://ftp.emea.ibm.com
- just login as anonymous
- Total Commander 7.50a or older connects and all is good
- Total Commander 7.55pb1 or later (of course including current 8.51a both 32 and 64 bit) disconnects during the connecting

7.50a:

...
SYST
215 UNIX is the operating system of this server. FTP Server is running on z/OS.
FEAT
211- Extensions supported
SIZE
MDTM
REST STREAM
UTF8
LANG en*
AUTH TLS
PBSZ
PROT
211 End
OPTS UTF8 ON
501 command OPTS aborted -- no options supported for UTF8
Connect ok!
PWD
257 "/" is the HFS working directory.
Get directory
TYPE A
200 Representation type is Ascii NonPrint
PORT 10,2,4,190,10,102
200 Port request OK.
LIST
125 List started OK
Download
Waiting for server...
250 List completed successfully.

8.51a:

...
1:SYST
1:215 UNIX is the operating system of this server. FTP Server is running on z/OS.
1:FEAT
1:211- Extensions supported
1: SIZE
1: MDTM
1: REST STREAM
1: UTF8
1: LANG en*
1: AUTH TLS
1: PBSZ
1: PROT
1:211 End
1:HELP SITE
1:214-The SITE command sub parameters are:
1:214-ASAtrans Specifies that ASA control characters in ASA files opened
1:214- for text processing should be converted to C control
1:214- character sequences during file transfer.
...
1:214-VCOUNT=value Maximum number of volumes for VOLUME statement.
1:OFFLINE6, error=0
1:Connect ok!

[ghisler(Author)]

It means that your server has a bug in the HELP SITE command. Total Commander sends the HELP SITE command to find out whether the server supports the command SITE UTIME to set the timestamp of uploaded files. HELP SITE is only shown when the server doesn't report support for MFMT command (in FEAT).

To turn off HELP SITE, you need to disable FEAT command too. But this means that UTF8 isn't auto-detected either. Therefore you need to:

1. Add
PreventFEAT=1
in wcx_ftp.ini under section [General]
2. In the connection settings, set the encoding manually to UTF8 since in the above log the server reports to support UTF8.