The error i've faced with it:

OpenERP Server Error

Traceback (most recent call last):

File "/opt/odoo/v8/server/openerp/http.py", line 470, in dispatch

result = self._call_function(**self.params)

File "/opt/odoo/v8/server/openerp/http.py", line 294, in _call_function

return checked_call(self.db, *args, **kwargs)

File "/opt/odoo/v8/server/openerp/service/model.py", line 113, in wrapper

return f(dbname, *args, **kwargs)

File "/opt/odoo/v8/server/openerp/http.py", line 291, in checked_call

return self.endpoint(*a, **kw)

File "/opt/odoo/v8/server/openerp/http.py", line 638, in __call__

return self.method(*args, **kw)

File "/opt/odoo/v8/server/openerp/http.py", line 337, in response_wrap

response = f(*args, **kw)

File "/opt/odoo/v8/web/addons/web/controllers/main.py", line 1244, in call_kw

return self._call_kw(model, method, args, kwargs)

File "/opt/odoo/v8/web/addons/web/controllers/main.py", line 1236, in _call_kw

return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)

TypeError: read_group() got an unexpected keyword argument 'lazy'