You receive the following error when publishing your workflow in Office 365:
(Error publishing workflow. NW-2-002)
This error occurs when trying to publish a workflow and the "Workflow Tasks" list does not exist or may have been deleted. Normally, the "Workflow Tasks" list should be created upon opening the Nintex Workflow Designer. If this was not successful or perhaps that list was deleted while you were in designer you will receive this error.
To resolve this error simply close the workflow designer and review your site contents to ensure the workflow tasks list has been created or not. If the workflow tasks list has been created simply open the designer again and publish your workflow.