IntegrityError: null value in column "sender" violates not-null constraint

[tobiasmcnulty]

Traceback (most recent call last):

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/core/handlers/base.py", line 112, in get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/newrelic-2.22.1.20/newrelic/hooks/framework_django.py", line 492, in wrapper
    return wrapped(*args, **kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/views/generic/base.py", line 69, in view
    return self.dispatch(request, *args, **kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/views/decorators/csrf.py", line 57, in wrapped_view
    return view_func(*args, **kwargs)

  File "/var/www/myvoice/source/myvoice/clinics/views.py", line 30, in dispatch
    return super(VisitView, self).dispatch(*args, **kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/newrelic-2.22.1.20/newrelic/hooks/framework_django.py", line 829, in wrapper
    return wrapped(*args, **kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/views/generic/base.py", line 87, in dispatch
    return handler(request, *args, **kwargs)

  File "/var/www/myvoice/source/myvoice/clinics/views.py", line 48, in post
    models.Visit.objects.create(patient=patient, service=serv, mobile=mobile, sender=sender)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/manager.py", line 157, in create
    return self.get_queryset().create(**kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/query.py", line 322, in create
    obj.save(force_insert=True, using=self.db)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/base.py", line 545, in save
    force_update=force_update, update_fields=update_fields)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/base.py", line 573, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/base.py", line 654, in _save_table
    result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/base.py", line 687, in _do_insert
    using=using, raw=raw)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/manager.py", line 232, in _insert
    return insert_query(self.model, objs, fields, **kwargs)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/query.py", line 1514, in insert_query
    return query.get_compiler(using=using).execute_sql(return_id)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 903, in execute_sql
    cursor.execute(sql, params)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/backends/util.py", line 53, in execute
    return self.cursor.execute(sql, params)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/utils.py", line 99, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/django/db/backends/util.py", line 53, in execute
    return self.cursor.execute(sql, params)

  File "/var/www/myvoice/env/local/lib/python2.7/site-packages/newrelic-2.22.1.20/newrelic/hooks/database_dbapi2.py", line 22, in execute
    *args, **kwargs)

IntegrityError: null value in column "sender" violates not-null constraint