TypeError: can't pickle module objects

Hi, i am facing problem with installing custom app . let me know if anybody faced same error and how can i solve this one

i am using
erpnext 12.10.1
frappe 12.8.4

Traceback (most recent call last):
File “/home/abrar/onefm-bench/apps/frappe/frappe/app.py”, line 73, in application
response = frappe.website.render.render()
File “/home/abrar/onefm-bench/apps/frappe/frappe/website/render.py”, line 36, in render
File “/home/abrar/onefm-bench/apps/frappe/frappe/website/redirect.py”, line 23, in resolve_redirect
redirects = frappe.get_hooks(‘website_redirects’)
File “/home/abrar/onefm-bench/apps/frappe/frappe/init.py”, line 958, in get_hooks
hooks = _dict(cache().get_value(“app_hooks”, load_app_hooks))
File “/home/abrar/onefm-bench/apps/frappe/frappe/utils/redis_wrapper.py”, line 82, in get_value
self.set_value(original_key, val, user=user)
File “/home/abrar/onefm-bench/apps/frappe/frappe/utils/redis_wrapper.py”, line 50, in set_value
self.set(key, pickle.dumps(val))
TypeError: can’t pickle module objects

before getting custom app set developer mode in site_config.json. And download ,install and migrate the custom app