Erpnext installation issue with "Sorry! We will be back soon."

[MartinHBramwell]

You are seeing this :

ModuleNotFoundError: No module named 'werkzeug.contrib' (erpnext 12.4.3)

Immediately after installation, this error appears dozens of times in my log file: /home/erpnext/frappe-bench/logs/web.error.log Traceback (most recent call last): File "/home/erpnext/frappe-bench/env/bin/gunicorn", line 8, in <module> sys.exit(run()) File "/home/erpnext/frappe-bench/env/lib/python3.6/site-packages/gunicorn/app/wsgiapp.py", line 58, in run WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run() File "/home/erpnext/frappe-bench/env/lib/python3.6/site-packages/gun…