Nintex workflow scheduler

Hi,

Could you please provide more details about the workflow content and its scheduling?

From my own experience, there's no reason that your farm topology could lead to this behavior.

Here is SharePoint ULS log for the designated schedule time where workflow is errored.

: Nintex.Workflow.NWException: Workflow schedule failed. Schedule details can be viewed at: https://myspsite/sites/spsubsite/_layouts/15/NintexWorkflow/NewWorkflowSchedule.aspx?ListId={00000000-0000-0000-0000-000000000000}&ItemId=-1&ScheduleId=9 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.SharePoint.Workflow.SPWinOeHostServices.EnsurePluggableServices(SPSite site, SPWorkflowExternalDataExchangeServiceCollection services, ExternalDataExchangeService existingServices)
at Microsoft.SharePoint.Workflow.SPWinOeHostServices..ctor(SPSite site, SPWeb web, SPWorkflowManager manager, SPWorkflowEngine engine) -
-- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, StackCrawlMark& stackMark)
at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Reflection.Assembly.CreateInstance(String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.LoadPluggableClass(String classname, String assembly, Object[] parameters)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.GetService(SPWorkflowAssociation association, SPWorkflowEngine engine)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.RunWorkflowElev(SPWorkflow workflow, Collection`1 events, SPWorkflowRunOptionsInternal runOptions)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.StartWorkflowElev(Object context, SPWorkflowAssociation association, DateTime elevationTimeUtc, SPWorkflowEvent startEvent, SPWorkflowRunOptions runOptions)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.<>c__DisplayClass16.<StartWorkflow>b__15(SPSite superUserSite, SPWeb superUserWeb)
at Microsoft.SharePoint.SPSecurity.<>c__DisplayClassd.<RunWithSystemSiteAndWeb>b__b()
at Microsoft.SharePoint.SPSecurity.<>c__DisplayClass5.<RunWithElevatedPrivileges>b__3()
at Microsoft.SharePoint.Utilities.SecurityContext.RunAsProcess(CodeToRunElevated secureCode)
at Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(WaitCallback secureCode, Object param)
at Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(CodeToRunElevated secureCode)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.StartWorkflow(Object context, SPWorkflowAssociation association, SPWorkflowEvent startEvent, SPWorkflowRunOptions runOpts)
at Microsoft.SharePoint.Workflow.SPWorkflowManager.StartWorkflow(Object context, SPWorkflowAssociation association, String eventData, SPWorkflowRunOptions runOptions)
at Nintex.Workflow.Scheduling.WorkflowScheduleItem.Execute()
at Nintex.Workflow.Scheduling.WorkflowSchedulerJob.Execute(Guid targetInstanceId) -
-- End of inner exception stack trace --- (Build:3160)

Hi,

Based on stack exception, I found this post on the community :

The infamous "failed to run" errors in the history list. 

Did you ever read this?

It is not exactly the same error but it could help to understand.