title: Cannot resolve keyword 'xxx' into field. Choices are: full_name, id, title
body: <p>I'm getting a strange error for one of my classes and I don't know why.</p>
  
  <p>I have a Grade model:</p>
  
  <pre><code>class SchoolGrade(models.Model):
      title = models.CharField('Grade',max_length=10, null=True, blank=True)
      full_name = models.CharField('Description',max_length=100, null=True, blank=True)
  
      def __unicode__(self):
          return self.full_name
  
      class Meta:
          ordering = ('full_name',)
  </code></pre>
  
  <p>I also have a Videos model:</p>
  
  <pre><code>class Video(models.Model):
  
      active = models.BooleanField(default=True)    
      title = models.CharField('Gallery Name',max_length=255, null=True, blank=True)
      seo = models.SlugField('SEO Field',max_length=255, null=True, blank=True)    
      description = models.TextField(null=True, blank=True)
      gender = models.CharField(choices=GENDERS, max_length=1, default='u', null=True, blank=True)
      ages = models.ManyToManyField(Age, related_name='videos', null=True, blank=True)
      grades = models.ManyToManyField(SchoolGrade, verbose_name='Grades', related_name='grade_videos', null=True, blank=True)
  </code></pre>
  
  <p>Now, the problem is that whenever I try to open ANY video in the Admin, I get the exception error:</p>
  
  <pre><code>FieldError at /admin/videos/video/150/
  Cannot resolve keyword 'grade_videos' into field. Choices are: full_name, id, title
  </code></pre>
  
  <p>The Age model referenced above is just as simple as the SchoolGrade model is:</p>
  
  <pre><code>class Age(models.Model):
  
      name = models.CharField(max_length=25, unique=True)
      slug = models.SlugField(null=True, blank=True)
  
      def __unicode__(self):
          return self.name
  
      class Meta:
          ordering = ('name',)
  </code></pre>
  
  <p>I don't get any errors on this model, ONLY the SchoolGrade model. </p>
  
  <p>Lastly, everything works fine on the localhost server. This only occurs on the webserver. The Python, database and Django versions are all identical. </p>
  
  <p>Several others had this error and I tried all of their suggestions. I guess I was hoping someone else might have had my exact problem.</p>
  
  <p>Thank you in advance,</p>
  
  <p>L.</p>
  
  <p><strong>Age &amp; SchoolGrade</strong></p>
  
  <pre><code>class AgeAdmin(admin.ModelAdmin):
  
      list_display = ('name','slug',)
      prepopulated_fields = {"slug" : ('name',)}
  
  class SchoolGradesAdmin(admin.ModelAdmin):
  
      list_display = ('title','full_name',)
  
  
  admin.site.register(Age, AgeAdmin)
  admin.site.register(SchoolGrade, SchoolGradesAdmin)
  </code></pre>
  
  <p><strong>Video</strong></p>
  
  <pre><code>class VideoAdmin(admin.ModelAdmin):
  
      list_display = ('title','the_cats','the_grades','good_for','widget_name','active','featured','date_released')
      search_fields = ['title','description_markdown',]
      list_filter = ['active','featured','gender','grades','galleries','widget_name']
      prepopulated_fields = {"slug" : ('title',)}
      fieldsets = [
          (None, {'fields': (('active','featured'),'display_order', ('title', 'slug'),'grades','galleries',('gender', 'gender_scale'),'widget_name','good_for','quiz','description_markdown','why_like_markdown')}),
      ]
      formfield_overrides = {
          WYWIWYGField: {'widget': TinyMCE(attrs={'cols': 100, 'rows': 30})},
      }
      inlines = [VideoRankingInline, VideoAssetsInline]
  
  admin.site.register(Video, VideoAdmin)
  </code></pre>