Final answer:
To address a duplicate ID error in an update process, the practitioner should inspect the data by displaying the target of the population and analyzing the IDs to identify the cause of the duplicates.
Step-by-step explanation:
When an update process fails due to a duplicate ID error, the first step a Campaign Business Practitioner should take to determine the root cause is to right-click and display the target of the population, add columns to analyze the IDs, and add columns to assess a possible cause. This step will help to visually inspect the data for any obvious issues such as duplicate IDs. It places an emphasis on understanding the data within the system before taking other actions, such as reaching out to an administrator or altering the workflow logic. If duplicate IDs are found, one must then trace back to see where these duplicates are originating from, be it from a data import process or a flaw within the workflow logic itself.