mI got the following error while running the demo with "make runserver":django.db.utils.OperationalError: Problem installing fixture '/home/ruihai.jing/TTProgram/django-downloadview-master/demo/demoproject/fixtures/demo.json': Could not load object.Document(pk=1): no such table: object_document #157
django.db.utils.OperationalError: Problem installing fixture '/home/ruihai.jing/TTProgram/django-downloadview-master/demo/demoproject/fixtures/demo.json': Could not load object.Document(pk=1): no such table: object_document
django.db.utils.OperationalError: Problem installing fixture '/home/ruihai.jing/TTProgram/django-downloadview-master/demo/demoproject/fixtures/demo.json': Could not load object.Document(pk=1): no such table: object_document