Workflow fails randomly, after an update action.

Hi,

For SharePoint on premise, Nintex uses SharePoints legacy workflow engine.  As that is the case, Nintex experiences all the quirks of that engine.

Pauses.

When you use a pause action, the delay you specify is not how long the workflow pauses before continuing. The delay is how long the workflow waits before adding the workflow back into the workflow timer service queue. The workflow timer service runs every five minutes so yes, your delay is longer than 12 seconds.

Why? 

This issue occurs because your environment is very fast. When SharePoint performs an operation on an item it puts a lock on the item so that no other process can make changes at the same time. In this case, SharePoint has not released the lock before the next action starts its operation so an error occurs.

Fix

As you have seen, the only fix is to wait for SharePoint to release its lock (pause) before performing the next action.