NoReverseMatch at /admin/plans/order/1/change/

[maxpaynestory]

I am getting the following error. Can anybody help me.

Request Method: | POST
Request URL: http://django.vm:8000/admin/plans/order/1/change/
Django Version: 2.0.5
Exception Type: NoReverseMatch
Exception Value: Reverse for 'invoice_preview_html' not found. 'invoice_preview_html' is not a valid view function or pattern name.
Exception Location: /usr/local/lib/python3.4/dist-packages/django/urls/resolvers.py in _reverse_with_prefix, line 632
Python Executable: /usr/bin/python3
Python Version: 3.4.3