While debugging an issue with cookie path attributes not appearing to be checked I changed the Application Session configuration to use 'Memory'. I found the AppServer dies with a traceback due to app._sessionDir being None. Turns out the SessionMemoryStore class needs the SessionStoreDir attribute set since it uses a SessionFileStore instance to load/save sessions to disk on startup/shutdown.

The fix is in Application.py line 350 - old code:
        self._sessionDir = moduleName != 'SessionMemoryStore' \
            and self.serverSidePath(
                self.setting('SessionStoreDir') or 'Sessions') or None

New code:
        self._sessionDir = self.serverSidePath(self.setting('SessionStoreDir') or 'Sessions')

With this change SessionMemoryStore will write session to the configured location or to the local dir's Sessions directory.

Best Regards,