[Django]-Why does my aging Django 1.3.1 site say ''TemplateDoesNotExist at /admin/" after migration to a new server?

Looks like my Django install was corrupted (including pip’s cache of it). The following sorted it out:

rm -rf ~/.cache/pip
pip2.7 uninstall django
pip2.7 install django==1.3.1 --no-cache-dir

Solved thanks to the answer here.