I got the same error 3 times already, before I didn't find the solution in Google nor here, and I guess I'm not the only one who got it.
From a fresh installation, I install at the same time the django-cms plugin an many of its plugins.
After running
python manage.py makemigrations
python manage.py migrate
I get this error: django.db.utils.ProgrammingError: relation "cms_cmsplugin" does not exist