Unexpected Termination of Nintex Workflow

Hello ​@FUKUSHIMA 
Please use English going forward, so all users can understand and assist!

Google Translation:
Subject: Unexpected Termination of Nintex Workflow

To Nintex Support Team

Thank you for your continued support.

This is Fukushima from Kaneka.

I would like to request your assistance in investigating the cause of an issue with a site workflow running on Nintex Workflow for SharePoint 2016.

■ Installed Products
・Nintex Workflow for SharePoint 2016 - International
・Version: 4.3.3.0

■ SharePoint Server Version
・SharePoint Server 2016 (On-Premise)

■ Server Configuration
・SharePoint WFE role and APP role run on the same server
・IIS (w3wp.exe), SharePoint Timer Service,
SPUCHostService.exe (Nintex Workflow / User Code) run on the same server
・SQL Server is on a separate server
・DocAve 6 server for backup purposes
・Total of 3 servers

■ Affected Workflow
Completion Catalog Submission Reminder Email Sending WF

■ Incident
The following error notification email was received for the above workflow, which is running on a schedule:

"The Completion Catalog Submission Reminder Email Sending WF workflow terminated unexpectedly."

■ Occurrence Date and Time
*This issue has been occurring almost daily for over 5 months. The following is the most recent occurrence date and time.

2026/07/08 09:03 AM

■ What we have confirmed

The workflow is executed on a daily schedule.

The workflow execution history records various processes and log outputs.

We have confirmed that reminder emails are actually sent.

We have received error notification emails, but the notification emails do not contain detailed exception information or error details.

We are unable to identify the specific error location or exception details from the workflow history.

The workflow performs loop processing, XML information retrieval, and email sending processing.

■ Things we would like you to confirm

Please tell us the main reasons why the notification "Workflow terminated unexpectedly" is displayed.

Is there a place where we can check more detailed error information?

Please let us know if there are any other logs we should check besides the workflow history (Nintex logs, ULS logs, etc.).

Please let us know if there is any additional information we should provide to help us investigate this issue.

We can also share screenshots of the workflow history and design screen if necessary.

We apologize for the inconvenience, but please check this for us.

Hi ​@FUKUSHIMA 

For reviewing more detailed errors in workflows you’d want to look at the ULS logs.  You should be able to find the workflow Instance ID in the logs around the time of the failure to give you what correlation ID to review, then filter on that correlation ID to find out more about what’s occurring.

For a more detailed review of what’s causing the failures, I’d recommend reaching out to support.   They should be able to review the logs to help identify what’s occurring.