PRB: FTP WinInet APIs Report Error 12003
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.
Connection to a non-Microsoft FTP server with WinInet FTP APIs may failwith error 12003.
When connecting to a non-Microsoft FTP server with WinInet APIs, someWinInet FTP APIs may fail with error 12003 (ERROR_INTERNET_EXTENDED_ERROR).The InternetGetLastResponseInfo API may not retrieve any Internet specificinformation. This error may occur when the FTP server sends an unexpectedstatus code to the WinInet client. Please note that this may not indicatean error, but rather the server's success message or confirmation (such asconfirmation of getting a file, sending a directory listing, and so forth).In some cases the WinInet FTP APIs may not parse such messages correctlyand erroneously report an error. This may happen when the WinInet FTP APIsare used to connect to certain VAX/VMS FTP servers.
The above behavior may be avoided by not using the INTERNET_FLAG_PASSIVEflag in the InternetConnect or InternetOpenUrl API. When this flag is notused WinInet uses active semantics for the FTP connection, which avoids thereturn of the status code, which causes the parsing problem.
See FTP Protocol Specification (RFC 959) for more information.
Article ID: 168492 - Last Review: 06/22/2014 18:22:00 - Revision: 3.0