OpenERP Server Error

Client Traceback (most recent call last): File "/opt/openerp/server/openerp/addons/web/http.py", line 204, in dispatch response["result"] = method(self, **self.params) File "/opt/openerp/server/openerp/addons/web/controllers/main.py", line 1128, in call_kw return self._call_kw(req, model, method, args, kwargs) File "/opt/openerp/server/openerp/addons/web/controllers/main.py", line 1120, in _call_kw return getattr(req.session.model(model), method)(*args, **kwargs) File "/opt/openerp/server/openerp/addons/web/session.py", line 42, in proxy result = self.proxy.execute_kw(self.session._db, self.session._uid, self.session._password, self.model, method, args, kw) File "/opt/openerp/server/openerp/addons/web/session.py", line 30, in proxy_method result = self.session.send(self.service_name, method, *args) File "/opt/openerp/server/openerp/addons/web/session.py", line 103, in send raise xmlrpclib.Fault(openerp.tools.ustr(e), formatted_info) Server Traceback (most recent call last): File "/opt/openerp/server/openerp/addons/web/session.py", line 89, in send return openerp.netsvc.dispatch_rpc(service_name, method, args) File "/opt/openerp/server/openerp/netsvc.py", line 296, in dispatch_rpc result = ExportService.getService(service_name).dispatch(method, params) File "/opt/openerp/server/openerp/service/web_services.py", line 626, in dispatch res = fn(db, uid, *params) File "/opt/openerp/server/openerp/osv/osv.py", line 190, in execute_kw return self.execute(db, uid, obj, method, *args, **kw or {}) File "/opt/openerp/server/openerp/osv/osv.py", line 132, in wrapper return f(self, dbname, *args, **kwargs) File "/opt/openerp/server/openerp/osv/osv.py", line 199, in execute res = self.execute_cr(cr, uid, obj, method, *args, **kw) File "/opt/openerp/server/openerp/addons/audittrail/audittrail.py", line 532, in execute_cr return fct_src(cr, uid, model, method, *args, **kw) File "/opt/openerp/server/openerp/osv/osv.py", line 187, in execute_cr return getattr(object, method)(cr, uid, *args, **kw) File "/opt/openerp/server/openerp/osv/orm.py", line 2672, in read_group self._apply_ir_rules(cr, uid, query, 'read', context=context) File "/opt/openerp/server/openerp/osv/orm.py", line 4816, in _apply_ir_rules rule_where_clause, rule_where_clause_params, rule_tables = rule_obj.domain_get(cr, uid, self._name, mode, context=context) File "/opt/openerp/server/openerp/addons/base/ir/ir_rule.py", line 150, in domain_get dom = self._compute_domain(cr, uid, model_name, mode) File "/opt/openerp/server/openerp/tools/cache.py", line 18, in lookup r = self.lookup(self2, cr, *args) File "/opt/openerp/server/openerp/tools/cache.py", line 46, in lookup value = d[key] = self.method(self2, cr, *args) File "/opt/openerp/server/openerp/addons/base/ir/ir_rule.py", line 130, in _compute_domain rule_domain = self.read(cr, uid, rule.id, ['domain'])['domain'] File "/opt/openerp/server/openerp/osv/orm.py", line 3679, in read result = self._read_flat(cr, user, select, fields, context, load) File "/opt/openerp/server/openerp/osv/orm.py", line 3800, in _read_flat res2 = self._columns[f].get(cr, self, ids, f, user, context=context, values=res) File "/opt/openerp/server/openerp/osv/fields.py", line 1145, in get result = self._fnct(obj, cr, uid, ids, name, self._arg, context) File "/opt/openerp/server/openerp/addons/base/ir/ir_rule.py", line 53, in _domain_force_get res[rule.id] = expression.normalize_domain(eval(rule.domain_force, eval_context)) File "/opt/openerp/server/openerp/tools/safe_eval.py", line 285, in safe_eval return eval(test_expr(expr, _SAFE_OPCODES, mode=mode), globals_dict, locals_dict) File "", line 1, in <module> AttributeError: 'NoneType' object has no attribute 'id'