title: multiple authentication backends configured and therefore must provide the `backend` argument or set the `backend` attribute on the user
body: <p>first of i am new to <code>django/python</code> .</p>
  <p>i am trying to create a login website that allows the user to register an <code>account</code> and <code>verify</code> via <code>email</code> or directly <code>login</code> via <code>fb</code> or <code>google</code>(<code>Oauth</code>)</p>
  <p>i receive the error when i click on the validation url sent to the <code>email</code>.</p>
  <p><code>error</code>:</p>
  <pre><code>ValueError at /activate/Mjk/4p1-dcc5f7ed2e7c847fe362/
  
  You have multiple authentication backends configured and therefore must 
  
  provide the `backend` argument or set the `backend` attribute on the user.
  
  Request Method: GET
  
  Request URL:    http://127.0.0.1:8000/activate/Mjk/4p1-dcc5f7ed2e7c847fe362/
  Django Version: 1.11.3
  
  Exception Type: ValueError
  
  Exception Value:    
  
  You have multiple authentication backends configured and therefore must provide the `backend` argument or set the `backend` attribute on the user.
  Exception Location: /usr/local/lib/python2.7/dist-packages/django/contrib/auth/__init__.py in login, line 149
  Python Executable:  /usr/bin/python
  Python Version: 2.7.12
  Python Path:    
  ['/home/gaby/django projects/simple-signup-master/profile-model',
   '/usr/local/lib/python2.7/dist-packages/virtualenv-15.1.0-py2.7.egg',
   '/usr/lib/python2.7',
   '/usr/lib/python2.7/plat-x86_64-linux-gnu',
   '/usr/lib/python2.7/lib-tk',
   '/usr/lib/python2.7/lib-old',
   '/usr/lib/python2.7/lib-dynload',
   '/home/gaby/.local/lib/python2.7/site-packages',
   '/usr/local/lib/python2.7/dist-packages',
   '/usr/lib/python2.7/dist-packages',
   '/usr/lib/python2.7/dist-packages/PILcompat',
   '/usr/lib/python2.7/dist-packages/gtk-2.0',
   '/usr/lib/python2.7/dist-packages/ubuntu-sso-client']
  Server time:    Wed, 30 Aug 2017 12:34:31 +0000
  </code></pre>
  <h1>mysite/settings</h1>
  <pre><code>AUTHENTICATION_BACKENDS = (
  
      
       'social_core.backends.facebook.FacebookOAuth2',
       'social_core.backends.google.GoogleOAuth2',
  
       'django.contrib.auth.backends.ModelBackend',
  )
  </code></pre>
  <h1>this is the function being called when i receive the error</h1>
  <pre><code>    def activate(request, uidb64, token):
      try:
      uid = force_text(urlsafe_base64_decode(uidb64))
      user = User.objects.get(pk=uid)
      except (TypeError, ValueError, OverflowError, User.DoesNotExist):
      user = None
  
      if user is not None and account_activation_token.check_token(user, 
      token):
      user.is_active = True
      user.profile.email_confirmed = True
      user.save()
      login(request, user)
      return redirect('home')
  else:
      return render(request, 'account_activation_invalid.html')
  </code></pre>
  <p>i started receiving the <code>error</code> after adding the <code>oath</code> login via <code>fb</code>,<code>google</code>.
  if i remove'<code>social_core.backends.facebook.FacebookOAuth2</code>','<code>social_core.backends.google.GoogleOAuth2</code>' from <code>AUTHENTICATION_BACKENDS</code> the <code>email confirmation</code> will work again.</p>
  <p>i searched online and also here the only solution that i found was below but it didn't solve my problem.</p>
  <p><a href="https://stackoverflow.com/questions/17064443/django-multiple-authentication-backend-for-one-project-how">here</a></p>