Editinng rpc.py file in GTK Client (add "allow_none=True" to all xmlrpclib.ServerProxy calls in rpc.py), the problem is not fixed.
Problem is fixed edit wsgi/core.py file in openerp-server (edit all "xmlrpclib.dumps(fault, allow_none=False, encoding=None)" to "xmlrpclib.dumps(fault, allow_none=True, encoding=None)" ), so works.
I do not know - whether it is correct.
Editinng rpc.py file in GTK Client (add "allow_none=True" to all xmlrpclib. ServerProxy calls in rpc.py), the problem is not fixed.
Problem is fixed edit wsgi/core.py file in openerp-server (edit all "xmlrpclib. dumps(fault, allow_none=False, encoding=None)" to "xmlrpclib. dumps(fault, allow_none=True, encoding=None)" ), so works.
I do not know - whether it is correct.