Topic
When trying to create a package with a workflow that has a Call Sub Workflow step, the Package and Deployment tool showed the following error for that workflow:Ensure that your workflow is deployed before packaging. The Workflow Setting could not be found.
Clicking on the error message reveals the error in the sub-workflow. The main and sub-workflows can be deployed with Designer, and there are no errors when running the workflows.

Instructions
This can happen if the sub-workflow's name has a trailing whitespace. To check if the sub-workflow has any trailing whitespace, you can use the following queries on your Nintex Automation database.
-- Checks the deployed copy of the workflowSELECT '[' + [Name] + ']', '[' + [FullName] + ']'FROM [Server].[ProcSet]WHERE [Name] LIKE '%Sub Workflow%'-- Checks the copy of the workflow on DesignerSELECT '[' + [Name] + ']'FROM [Designer].[Process]WHERE [Name] LIKE '%Sub Workflow%'
The above queries will surround the name of the workflow with brackets. If there is a trailing whitespace in the name, you can notice it in the results. Example:

If there is a trailing whitespace in your sub-workflow's name, the recommended solution is to create a copy of the sub-workflow, but this time, make sure there is no trailing whitespace in the workflow's name. Once you have created a copy of the sub-workflow, deploy it and reconfigure the main workflow's Call Sub Workflow step to use the new copy of the sub-workflow and deploy the changes. After that, you should be able to create a package with those workflows.