NereidModuleError2

Traceback (most recent call last):
  File "/trytond/protocols/jsonrpc.py", line 125, in _marshaled_dispatch
    response['result'] = dispatch_method(method, params)
  File "/trytond/protocols/jsonrpc.py", line 158, in _dispatch
    res = dispatch(*args)
  File "/trytond/protocols/dispatcher.py", line 158, in dispatch
    result = rpc.result(meth(*c_args, **c_kwargs))
  File "/trytond/wizard/wizard.py", line 225, in execute
    return wizard._execute(state_name)
  File "/trytond/wizard/wizard.py", line 256, in _execute
    result = self._execute(transition())
  File "/trytond/ir/module/module.py", line 518, in transition_upgrade
    pool.init(update=True, lang=lang)
  File "/trytond/pool.py", line 151, in init
    lang=lang)
  File "/trytond/modules/__init__.py", line 433, in load_modules
    _load_modules()
  File "/trytond/modules/__init__.py", line 396, in _load_modules
    load_module_graph(graph, pool, lang)
  File "/trytond/modules/__init__.py", line 251, in load_module_graph
    tryton_parser.parse_xmlstream(fp)
  File "/trytond/convert.py", line 441, in parse_xmlstream
    self.sax_parser.parse(source)
  File "/xml/sax/expatreader.py", line 107, in parse
    xmlreader.IncrementalParser.parse(self, source)
  File "/xml/sax/xmlreader.py", line 123, in parse
    self.feed(buffer)
  File "/xml/sax/expatreader.py", line 210, in feed
    self._parser.Parse(data, isFinal)
  File "/xml/sax/expatreader.py", line 304, in start_element
    self._cont_handler.startElement(name, AttributesImpl(attrs))
  File "/trytond/convert.py", line 456, in startElement
    self.taghandler.startElement(name, attributes)
  File "/trytond/convert.py", line 181, in startElement
    self.model = self.mh.pool.get(attributes["model"])
  File "/trytond/pool.py", line 168, in get
    return self._pool[self.database_name][type][name]
KeyError: u'nereid.url_map'