Symptoms

Tasks during the processing fail with a message similar to this: 

The task {1792CB05-C841-4449-90A6-CFEFA0FA985B} failed after the final attempt to execute its subtask failed. Maximum number of attempts: 2."

Cause

One of the possible reasons for such behavior is a password lock on some or all documents in the batch. 

Resolution

The best way to avoid such a problem is to make sure that documents that are being processed are not locked under the password. In case it is not possible, it can be avoided by importing documents via a scanning station as explained in this article: How to process password-protected PDF files in ABBYY FlexiCapture 12.