The problem: Trying to ftp download one GIF image in a zope folder failed, the server give the following error message: ------ 1999-12-24T03:14:10 ERROR(200) ZServer exception in trigger thunk: (exceptions.AttributeError:'None' object has no attribute '_producers' [/home/maldf/Zope-2.1.0b2-src/ZServer/medusa/select_trigger.py|handle_read|82] [/home/maldf/Zope-2.1.0b2-src/ZServer/FTPResponse.py|apply|145] [/home/maldf/Zope-2.1.0b2-src/ZServer/FTPServer.py|retr_completion|360]) But many other GIF images never cause this problem in ftp download. The offending image is at http://www.zope.org/Members/LiDongfeng/test.gif The ftp client used is WS FTP LE version 5.06 on windows. The Zope server is version 2.1.0b2 on solaris 2.6. Anyone know the cause of this problem? PS: I have found the offending code in ZServer/FTPServer.py|retr_completion|360, it is: if not response._wrote: self.client_dc.push(response.body) else: for producer in response.stdout._producers: self.client_dc.push_with_producer(producer) obviously the response.stdout is None. Why this occured?