request) File   "/opt/virtualenvs/MY_SITE-a0hNfZxl/lib/python0.0/site-packages/wagtail/admin/edit_handlers.py"   in bind_to_instance     000.         new.on_instance_bound() File   "/opt/virtualenvs/MY_SITE-a0hNfZxl/lib/python0.0/site-packages/wagtail/admin/edit_handlers.py"   in on_instance_bound     000.                                                    request=self.request)) File   "/opt/virtualenvs/MY_SITE-a0hNfZxl/lib/python0.0/site-packages/wagtail/admin/edit_handlers.py"   in bind_to_instance     000.         new.on_instance_bound() File   "/opt/virtualenvs/MY_SITE-a0hNfZxl/lib/python0.0/site-packages/wagtail/admin/edit_handlers.py"   in on_instance_bound     000.                                                    request=self.request)) File   "/opt/virtualenvs/MY_SITE-a0hNfZxl/lib/python0.0/site-packages/wagtail/admin/edit_handlers.py"   in bind_to_instance     000.         new.on_instance_bound() File   "/opt/virtualenvs/MY_SITE-a0hNfZxl/lib/python0.0/site-packages/wagtail/admin/edit_handlers.py"   in on_instance_bound     000.         