"Please correct the error below." when saving add model form with inline formset and no auto primary key.
When a Model has a field with primary_key=True and the Admin has an Inline ManyToMany, trying to save will result in "Please correct the error below." with no errors shown.
This has been introduced in .
Just the changes in django/contrib/admin/options.py to be precise.
I expected reverting the patch would result in failing tests. But no tests failed.
So either  contained noise code that was doing nothing or it needed better tests.
I've written a test for my usecase that was broken by  and I suggest that someone that knows the purpose
of the options.py part of 12206 expresses that purpose in a test.
I'll add both my test and a patch containing part of the faulty changeset, but triagers, this ticket might need a better patch.