Issue
The workflow failed at a Send an Email action with The workflow has failed unexpectedly. [Error Code: Runtime.Internal] after user uploading and submitting the form again.
Error Code
The workflow has failed unexpectedly. [Error Code: Runtime.Internal]
Resolution
There is no way for user to fix the original workflow instance files anymore because the files are already removed due to session expiry (forms loaded >2hours without form submission). So user should reload a new form instance and resubmit the form.
Additional Information
When user loads a form instance with file upload control, there is a session created. This session will expire in around 2 hours (this is not configurable by user).When the files are attached to the forms but only submitted after 2 hours, the files would have been removed because it has past 2 hours since the form was loaded.This 2 hours session expiry is not the same clean up as in NWC settings. The one that user can configure to 7 days/indefinite is only for file cleanup when workflows complete. When user uses the Resubmit button to resubmit the workflow, it is expected that the resubmit will fail because when executing workflow, it will refer to the files uploaded by original workflow instance, which are already cleaned up due to session expiry.