Error after upgrading to V5

Hi, after I’ve upgraded to V5 I would get an error message when I clicked on the Installer app.

Traceback (innermost last):
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/app.py”, line 51, in application
response = frappe.handler.handle()
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/handler.py”, line 70, in handle
execute_cmd(cmd)
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/handler.py”, line 93, in execute_cmd
ret = frappe.call(method, **frappe.form_dict)
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/init.py”, line 742, in call
return fn(*args, **newargs)
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/desk/page/applications/applications.py”, line 14, in get_app_list
app_hooks = frappe.get_hooks(app_name=app)
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/init.py”, line 662, in get_hooks
hooks = _dict(load_app_hooks(app_name))
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/init.py”, line 635, in load_app_hooks
app_hooks = get_module(app + “.hooks”)
File “/home/ubuntu/frappe-bench/apps/frappe/frappe/init.py”, line 555, in get_module
return importlib.import_module(modulename)
File “/usr/lib/python2.7/importlib/init.py”, line 37, in import_module
import(name)
ImportError: No module named hooks