Bulk Edit operation for the Epic Link field fails with a NullPointerException if sub-tasks are included

Issue Summary

There is a bug in Jira that intermittently allows users to trigger bulk edit operations for the Epic Link field even if sub-tasks are included within the dataset selected:

JRASERVER-72283 - Validator for the Epic Link field fails intermittently for bulk edit operations involving sub-tasks

If you try to complete the operation, it will fail while displaying a NullPointerException.

Steps to Reproduce

1. Select a group of issues that includes sub-tasks via JQL.
2. Click on Tools > Bulk change all issues.
3. Select all issues, click on Next.
4. Select the Edit issues operation.
5. Select the Epic Link field and insert an Epic.
6. You may need to repeat this process a few times, as the validator fails intermittently.

Expected Results

• A validator should prevent the operation from being triggered.
  

Actual Results

• The user is able to trigger the operation, but it fails with a NullPointerException
  

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available