The bug was not completly fixed in Mailman 2.1.15. self.__timestamp is set after the loading AND parsing of the file. With large files the parsing may need 1-2 seconds and in the meantime a new file, but older then the self.__timestamp set after the parsing ist written: (1) Nov 16 21:02:54 2016 (57765) Try-Load config file /var/lib/mailman/lists/XY/config.pck -> Load (2) Nov 16 21:02:54 2016 (57765) 1479326518 mtime(/var/lib/mailman/lists/XY/config.pck) -> Check mtime (3) Nov 16 21:02:54 2016 (57765) 0 (self.__timestamp) -> self.__timestamp is not set -> Load-File (4) Nov 16 21:02:54 2016 (57765) 1479326574 (Time before Load of config.pck) -> Timestamp int(time.time()) before the loading of the pickle file. (5) Nov 16 21:02:55 2016 (57765) 1479326575 (Time after Loading unpickling File = self.__timestamp) -> Timestamp after the Loading of the pickle file. The unpickling needs some time due to large List with 200.000 subscribers The parsing needs 1 second, timestamps differ. (6) Nov 16 21:02:55 2016 (57765) Try-Loaded config file /var/lib/mailman/lists/neuerscheinungen/config.pck -> Reload/Check Pickle-File (7) Nov 16 21:02:55 2016 (57765) 1479326574 mtime(/var/lib/mailman/lists/XY/config.pck) -> Check mtime (file is older than self.__timestamp), but nervertheless changed after the Loading in (5) (8) Nov 16 21:02:55 2016 (57765) 1479326575 SelfTimestamp -> Wrong Data saved -- You received this bug notification because you are a member of Mailman Coders, which is subscribed to GNU Mailman. https://bugs.launchpad.net/bugs/266464 Title: Subscriber "disappears" after subscription To manage notifications about this bug go to: https://bugs.launchpad.net/mailman/+bug/266464/+subscriptions