i ran into this issue when using v2.4 with django v1.8. (i didn't previously read it isn't supported)
It's not in the release notes but django.db.model.Options many_to_many() now returns an ImmutableList which is really just a tuple with a bunch of warnings and hooks on it.

if we don't make this typecast change we get the following error

TypeError: can only concatenate tuple (not "list") to tuple

I'm not sure if this change is appropriate and not sure what, if any, additional tests to include with this .

I attempted to test this but must be doing something wrong.
Every test fails when trying to use cursor. most of the errors I get are

 Failed: Database access not allowed, use the "django_db" mark to enable

i followed the instructions here.
https://github.com/tomchristie/django-rest-framework/blob/version-2.4.x/CONTRIBUTING.md