Create New Task List Missing in Nintex Workflow 2010
Why the option to create new task list cannot be found within the Workflow settings window with Nintex 2010?
This option to create a new task list is not available from the Workflow settings window on Nintex 2010. You will need to create the task list in SharePoint then make the connection from the Workflow settings window.
The option to create new task list from the workflow settings window is available with Nintex 2013 and 2016.