traceback

Traceback (most recent call last):
  File "/opt/openerp/server/openerp/openerp/http.py", line 500, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/opt/openerp/server/openerp/openerp/http.py", line 517, in dispatch
    result = self._call_function(**self.params)
  File "/opt/openerp/server/openerp/openerp/http.py", line 283, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/opt/openerp/server/openerp/openerp/service/model.py", line 113, in wrapper
    return f(dbname, *args, **kwargs)
  File "/opt/openerp/server/openerp/openerp/http.py", line 280, in checked_call
    return self.endpoint(*a, **kw)
  File "/opt/openerp/server/openerp/openerp/http.py", line 733, in __call__
    return self.method(*args, **kw)
  File "/opt/openerp/server/openerp/openerp/http.py", line 376, in response_wrap
    response = f(*args, **kw)
  File "/opt/openerp/server/openerp/openerp/addons/web/controllers/main.py", line 870, in search_read
    return self.do_search_read(model, fields, offset, limit, domain, sort)
  File "/opt/openerp/server/openerp/openerp/addons/web/controllers/main.py", line 891, in do_search_read
    request.context)
  File "/opt/openerp/server/openerp/openerp/http.py", line 835, in proxy
    result = meth(cr, request.uid, *args, **kw)
  File "/opt/openerp/server/openerp/openerp/api.py", line 237, in wrapper
    return old_api(self, *args, **kwargs)
  File "/opt/openerp/server/openerp/openerp/models.py", line 5021, in search_read
    result = self.read(cr, uid, record_ids, fields, context=read_ctx)
  File "/opt/openerp/server/openerp/openerp/api.py", line 237, in wrapper
    return old_api(self, *args, **kwargs)
  File "/opt/openerp/server/openerp/openerp/models.py", line 3072, in read
    result = BaseModel.read(records, fields, load=load)
  File "/opt/openerp/server/openerp/openerp/api.py", line 235, in wrapper
    return new_api(self, *args, **kwargs)
  File "/opt/openerp/server/openerp/openerp/models.py", line 3104, in read
    self._read_from_database(stored)
  File "/opt/openerp/server/openerp/openerp/api.py", line 235, in wrapper
    return new_api(self, *args, **kwargs)
  File "/opt/openerp/server/openerp/openerp/models.py", line 3268, in _read_from_database
    res2 = self._columns[f].get(cr, self._model, ids, f, user, context=context, values=result)
  File "/opt/openerp/server/openerp/openerp/osv/fields.py", line 1312, in get
    result = self._fnct(obj, cr, uid, ids, name, self._arg, context)
  File "/opt/openerp/server/openerp/openerp/tooling-addons/tooling_management_system/model/tooling_tooling.py", line 52, in _get_part_name
    res[obj.id] = ', '.join(part_name)
TypeError: sequence item 0: expected string, bool found