Scheduling & Bursting tasks end in Warning with "Could not export instance : Could not open instance" message on phase 3

Scheduling & Bursting tasks end in Warning with "Could not export instance : Could not open instance" message on phase 3

Symptom

When you run a Scheduling and Bursting task with many destination, some of them fails to export document.
  1. Task is in warning state
  2. In Instance Summary you have one or many {document name} (ID: {instance id}), Kind: {document kind} : instance removed
  3. In Phase 3, you have warning logs "Could not export instance : Could not open instance"

Environment

OS: All
SAP BusinessObjects version:  all
WebPlatform version: all

Cause

The issue comes from the fact that an external process removed the instances before the end of the task.
External processes may be custom script or the BOBJ Instance Limits.

Resolution

Solution 1 : relaunch

As you are affected by limits, you can use the "relaunch failed destinations" feature, may it be by hand, or if your task is an external task with the associated URL.

Solution 2 : split task process

You may use the "split task process" feature so that you are never affected by limits. 
In "Configuration" tab, scroll down to the "Advanced" panel and configure the "split task process" option with a batch size lower than your limits.

Solution 3 : change or remove limits

In Business Objects extend the limit for the document or remove them.