We are running Nintex WF 2016 on-prem.
I have a workflow that calls a sub-workflow. The main workflow run fine, it calls the sub-workflow and executes several actions. However it errors just before a "Pause for Item Update" action that causes the sub and main workflow to end.
The error in the main workflow is: Error retrieving workflow data. Invalid workflow instance Id. Workflow Id's must be in the format (xxxxxxx-xxxx-xxxx-xxxxxxxxxxxx). The error in the sub-workflow is An error has occurred in <sub-wf name>.
I have gotten this error previously. Republishing the sub-workflow would resolve the error. But now that "fix" no longer works. I have not found anything that references this error.
Has anyone else ever see this error? Any ideas what the cause may be? (The SharePoint logs don't provide any helpful info.)