ValidationError when saving completed membership registration

Thalia Technicie
2020-03-04T17:07:01+01:00

### One-sentence description ### Current behaviour / Reproducing the bug Click save while observing a completed registration. Sentry Issue: [CONCREXIT-4](https://sentry.io/organizations/thalia/issues/1057927495/?referrer=gitlab_integration) ``` ValueError: 'RegistrationForm' has no field named 'email'. (14 additional frame(s) were not displayed) ... File "django/forms/forms.py", line 180, in errors self.full_clean() File "django/forms/forms.py", line 383, in full_clean self._post_clean() File "django/forms/models.py", line 405, in _post_clean self._update_errors(e) File "django/forms/models.py", line 379, in _update_errors self.add_error(None, errors) File "django/forms/forms.py", line 353, in add_error "'%s' has no field named '%s'." % (self.__class__.__name__, field)) ValidationError: {'email': ['A user with that email address already exists. Login using the existing account and renew the membership by visiting the account settings.'], 'student_number': ['A user with that student number already exists. Login using the existing account and renew the membership by visiting the account settings.'], 'username': ['A user with that username already exists.']} File "django/forms/models.py", line 403, in _post_clean self.instance.full_clean(exclude=exclude, validate_unique=False) File "django/db/models/base.py", line 1152, in full_clean raise ValidationError(errors) ``` ### Expected behaviour No crash, maybe even no save button available.