Nintex – Specified value is not supported for the urlOfFile parameter

Recently after a Ninxtex migration/version update we encountered the following error when trying to publish any workflow:

Windows Event Log Error:
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.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(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.Control.LoadRecursive()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

To resolve this, go to the hidden NintexWorkflows library and check the contents of each subfolder. If your site is http://farm/sites/test the URL would be http://farm/sites/test/NintexWorkflows. If any subfolder is empty (contains no files), delete the subfolder – you should be able to publish after that.

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