Symptoms:
When submitting concurrently large amounts of tasks to the next stage, some tasks are stuck in the Moving to next stage status.

Explanation:
A Batch Submit can contain up to 1,000 tasks per request. If the user tries to submit more than 1,000 tasks at the same time, several Batch Submit requests are created. For example, when submitting 2,300 tasks, there will be 3 batches created: two of 1,000 tasks each and another batch of 300 tasks.

The Batch Submit process has a retry mechanism: if it fails the first time, SDL TMS will retry 3 times. When retrying, SDL TMS processes exactly the same Batch Submit request, trying to process tasks that were already processed fine the first time - whereas this is not needed – and then retries two other times. However, SDL TMS sometimes never gets to process the next tasks, therefore failing and leaving tasks in the Moving to next stage status. The speed at which those Batch Submit requests are processed varies from one TMS implementation to another, depending on the server(s) used.

Resolution:
The solution provided in this hotfix identifies the tasks getting processed fine and removes them from the Batch Submit request used by the retry attempts. Therefore, if SDL TMS cannot process all tasks submitted concurrently by a user in the first attempt, the next attempt will focus only on the tasks not handled yet. Ultimately TMS manages to process all the tasks.