This seems to be the issue: https://github.com/sebleier/django-redis-cache/issues/195

Uninstalled the django-redis-cache package and reinstalled with option --no-binary. This worked and I was able to access the test site.

[Tue Oct 13 14:27:11.514122 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] self.load_middleware()
[Tue Oct 13 14:27:11.514128 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] File "/var/www/vhosts/django_cyversedev/venv/django_cyversedev/lib/python3.6/site-packages/django/core/handlers/base.py", line 58, in load_middleware
[Tue Oct 13 14:27:11.514132 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] mw_instance = middleware(handler)
[Tue Oct 13 14:27:11.514142 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] File "/var/www/vhosts/django_cyversedev/venv/django_cyversedev/lib/python3.6/site-packages/django/middleware/cache.py", line 72, in _init_
[Tue Oct 13 14:27:11.514147 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] self.cache = caches[self.cache_alias]
[Tue Oct 13 14:27:11.514153 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] File "/var/www/vhosts/django_cyversedev/venv/django_cyversedev/lib/python3.6/site-packages/django/core/cache/_init.py", line 79, in __getitem_
[Tue Oct 13 14:27:11.514157 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] cache = _create_cache(alias)
[Tue Oct 13 14:27:11.514163 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] File "/var/www/vhosts/django_cyversedev/venv/django_cyversedev/lib/python3.6/site-packages/django/core/cache/_init_.py", line 53, in _create_cache
[Tue Oct 13 14:27:11.514167 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] "Could not find backend '%s': %s" % (backend, e))
[Tue Oct 13 14:27:11.514179 2020] [wsgi:error] [pid 2831:tid 139703997429504] [remote 99.69.51.247:61628] django.core.cache.backends.base.InvalidCacheBackendError: Could not find backend 'redis_cache.RedisCache': cannot import name 'six'

From reading the comments on this issue, this issue appears to be from a bad release of django-redis-cache to 2.1.3 that should not have occurred. The --no-binary option can be used as a workaround, but hopefully this issue will be resolved with a new release of django-redis-cache. Chaitanya Kintali and Chester Dias, this raises the question of whether we should be specifying exact versions (that we know that work) for various packages. Thoughts?

Nowlan Freese - do please specify the version and update the playbook accordingly. Make a comment in the place where the version is specified referring to this ticket.

Pull request: https://bitbucket.org/lorainelab/bioviz-connect-playbooks/pull-requests/7/igbf-2562-specify-package-version

Merged.
attn: Nowlan Freese

Closing issue.