Please help in solving this issue,
Afetr upgrading to version 8 I got the error shown in some screens while it should send me a descriptive error message that I can follow to solve my problem.
Check the logs in frappe-bench/logs/frappe.log
no errors in frappe.log, but found this error in web.error.log 
[2017-05-15 15:36:48 +0000] [13156] [ERROR] Error handling request /
Traceback (most recent call last):
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/gunicorn/workers/sync.py”, line 135, in handle
self.handle_request(listener, req, client, addr)
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/gunicorn/workers/sync.py”, line 176, in handle_request
respiter = self.wsgi(environ, resp.start_response)
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/werkzeug/local.py”, line 228, in application
return ClosingIterator(app(environ, start_response), self.cleanup)
File “/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/werkzeug/wrappers.py”, line 291, in application
return f(*args[:-2] + (request,))(*args[-2:])
File “/home/frappe/frappe-bench/apps/frappe/frappe/app.py”, line 81, in application
response = handle_exception(e)
File “/home/frappe/frappe-bench/apps/frappe/frappe/app.py”, line 156, in handle_exception
response = frappe.utils.response.report_error(http_status_code)
File “/home/frappe/frappe-bench/apps/frappe/frappe/utils/response.py”, line 24, in report_error
frappe.errprint(frappe.utils.get_traceback())
File “/home/frappe/frappe-bench/apps/frappe/frappe/init.py”, line 244, in errprint
print(msg.encode(‘utf-8’))
TypeError: ‘module’ object is not callable
Do you remember what was the trigger?
Is your frappe repo updated?
Yes frappe repo is updated
This appears whenever a throw message from system happens.
I hashed the line:
/home/frappe/frappe-bench/apps/frappe/frappe/init.py", line 244, in errprint
print(msg.encode(‘utf-8’))
And the problem is solved, but this removes the logging.