Upon publishing your workflow you receive the following error:
SharePoint: urlOfFile Parameter name: Specified value is not supported for the urlOfFile parameter
This is an ambiguous error message generated by SharePoint regarding the urlOfFile property of the SPfile object that is being called when using the SPFileCollection class. The urlOfFile parameter represents the site-relative URL of the file the get_item method is attempting to pull from the collection.
Upon review the ULS logs you'll find the following stack trace:
System.ArgumentException: urlOfFile Parameter name: Specified value is not supported for the urlOfFile parameter.
at Microsoft.SharePoint.SPFileCollection.get_Item(String urlOfFile)
at Nintex.Workflow.WorkflowRepository.NameInUse(String workflowName, Guid listId, WorkflowType& workflowType)
at Nintex.Workflow.ApplicationPages.SetName.Page_Load(Object sender, EventArgs e)
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Web.UI.Control.OnLoad(EventArgs e)
at Microsoft.SharePoint.WebControls.UnsecuredLayoutsPageBase.OnLoad(EventArgs e)
at Microsoft.SharePoint.WebControls.LayoutsPageBase.OnLoad(EventArgs e)
at Nintex.Workflow.ServerControls.NintexLayoutsBase.OnLoad(EventArgs e)
at Nintex.Workflow.ApplicationPages.SetName.OnLoad(EventArgs e)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
This error message indicates the URL SharePoint is attempting to use in the get_item method is failing an "IsNullOrEmpty" check. If your workflow was named "TestWorkflow" SharePoint will look for your workflow file using the following URL: http://YourSite/NintexWorkflows/TestWorkflow/TestWorkflow.xoml
Most of the time this issue is being caused by workflow folder inside the "NintexWorkflows" hidden Library. This can be because of permissions to the directory, the folder/file being checked out or files within the folder not existing.
To resolve this, navigate to the hidden 'NintexWorkflows' library (http://yoursite/NintexWorkflows) and check the contents of the workflow sub-folder you are attempting to publish.
If the workflow sub-folder is empty (contains no files), delete the sub-folder – you should be able to publish after that.