Odoo 9.0 Getting bug in terminal when reload page.

Traceback (most recent call last):

File "/home/odoo9e/openerp/http.py", line 599, in _handle_exception

return super(JsonRequest, self)._handle_exception(exception)

File "/home/odoo9e/openerp/http.py", line 636, in dispatch

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

File "/home/odoo9e/openerp/http.py", line 315, in _call_function

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

File "/home/odoo9e/openerp/service/model.py", line 113, in wrapper

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

File "/home/odoo9e/openerp/http.py", line 308, in checked_call

result = self.endpoint(*a, **kw)

File "/home/odoo9e/openerp/http.py", line 887, in __call__

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

File "/home/odoo9e/openerp/http.py", line 465, in response_wrap

response = f(*args, **kw)

File "/home/odoo9e/openerp/addons/web/controllers/main.py", line 969, in call_button

action = self._call_kw(model, method, args, {})

File "/home/odoo9e/openerp/addons/web/controllers/main.py", line 957, in _call_kw

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

File "/home/odoo9e/openerp/service/model.py", line 113, in wrapper

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

File "/home/odoo9e/openerp/addons/web/controllers/main.py", line 956, in checked_call

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

File "/home/odoo9e/openerp/api.py", line 232, in wrapper

return old_api(self, *args, **kwargs)

File "/home/odoo9e/openerp/addons/base/module/module.py", line 459, in button_immediate_install

return self._button_immediate_function(cr, uid, ids, self.button_install, context=context)

File "/home/odoo9e/openerp/api.py", line 232, in wrapper

return old_api(self, *args, **kwargs)

File "/home/odoo9e/openerp/addons/base/module/module.py", line 533, in _button_immediate_function

registry = openerp.modules.registry.RegistryManager.new(cr.dbname, update_module=True)

File "/home/odoo9e/openerp/modules/registry.py", line 385, in new

openerp.modules.load_modules(registry._db, force_demo, status, update_module)

File "/home/odoo9e/openerp/modules/loading.py", line 337, in load_modules

loaded_modules, update_module)

File "/home/odoo9e/openerp/modules/loading.py", line 237, in load_marked_modules

loaded, processed = load_module_graph(cr, graph, progressdict, report=report, skip_modules=loaded_modules, perform_checks=perform_checks)

File "/home/odoo9e/openerp/modules/loading.py", line 123, in load_module_graph

load_openerp_module(package.name)

File "/home/odoo9e/openerp/modules/module.py", line 324, in load_openerp_module

__import__('openerp.addons.' + module_name)

File "/home/odoo9e/openerp/modules/module.py", line 61, in load_module

mod = imp.load_module('openerp.addons.' + module_part, f, path, descr)

File "/home/odoo9e/openerp/addons/website_less/__init__.py", line 1, in <module>

import ir_qweb

File "/home/odoo9e/openerp/addons/website_less/ir_qweb.py", line 276, in <module>

class SassAsset(StylesheetAsset, openerp.addons.base.ir.ir_qweb.SassAsset):

AttributeError: 'module' object has no attribute 'SassAsset'