Django 1.7升级错误:感谢的准备:模型还没有加载。

I am trying to upgrade a project from Django 1.6 to 1.7. So far, I have created a new virtualenv with all the same installs and upgraded the Django version to the new release. I need to upgrade from South, but had errors doing so, so I thought I'll initially just try runserver, and I get the following error:I am trying to upgrade a project from Django 1.