Dear Mr.Scheidler As soon as I received reply from you, I adapted patches that you recommended and found nothing is solved. To fix this problem, I added a log in “Zorp.py” to determine what kind of exception occurred. except AttributeError: ## LOG ## # This message indicates that the initialization function of # the given instance was not found in the policy file. ## import sys log(None, CORE_ERROR, 0, "Exception: %s, %s", (sys.exc_type,sys.exc_value)) log(None, CORE_ERROR, 0, "Instance definition not found in policy; instance='%s'", (names,)) And got the next message; Apr 07 22:16:24 (nosession): Exception: <type 'exceptions.AttributeError'>, 'module' object has no attribute 'SockAddrType' Apparently, this is the main cause of failure, I guess. Could you tell me how I can fix this? Thank you for reading. I'm using zorp_3.1.12 with libzorpll_3.1.8.0.2. And python 2.5, glib 2.0 and Linux 2.6.23.1-42.fc8(Fedora).