Python Error: No module named adminsortable2.management.commands.reorder

This is probably because you don't have package django_admin_sortable2 installed.

You can install it in command line via pip:

        pip install django_admin_sortable2
      

Install specific version:

        pip install "django_admin_sortable2==0.7.6"
      

Get more info about package via pypi.org: django_admin_sortable2