Admin.py

class CourseAdmin(admin.ModelAdmin):

list_display = ('course_code', 'title', 'short' )

 def save_model(self, request, obj, form, change):
    import os

    #obj.author = request.user
    dir_name = obj.course_code
    path = settings.MEDIA_ROOT +os.sep+'xml'+os.sep+dir_name

    #if user updates course name then course would be renames
    if change:
        dir_name = Course.objects.get(pk=obj.pk).course_code
        src = settings.MEDIA_ROOT +os.sep+'xml'+os.sep+dir_name      
        os.rename(src,path)
    else:
        if not os.path.exists(path):
            os.makedirs(path)
            obj.save()

        else:
            raise ValidationError('Bla Bla')


admin.site.register(Course, CourseAdmin)

when i raise validation Error it doesn't work and shows error page with Exception Type: Validation Error Exception Value:[u'Bla Bla']

django django-admin
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