Make sure you test functionality for Nintex on each SharePoint list and library expected to use Nintex Workflow or Nintex Forms.
To test functionality for Nintex Workflow (SharePoint document library)
Select the Library tab from the ribbon, click Workflow Settings, and then select Nintex Workflow to display the Nintex Workflow designer; add workflow actions and publish.
To test functionality for Nintex Workflow (SharePoint list)
Select the List tab from the List Tools ribbon, click Workflow Settings, and then select Nintex Workflow to display the Nintex Workflow designer; add workflow actions and publish.
To test functionality for Nintex Forms (SharePoint list only)
Select the List tab from the List Tools ribbon and then click Nintex Forms to display configuration options for the default Nintex form.