Issue Summary

As per this community announcement ,the creation of subtasks is restricted under higher hierarchy levels, such as Epics. Users are still able to convert a Story (with existing Subtasks) into an Epic, but there is no prompt or warning to address the Subtasks during this process. Since Epics are not intended to have Subtasks, this may lead to unexpected hierarchy and data integrity issues.

Steps to Reproduce

1. Create a Story
2. Add one or more Subtasks to the Story.
3. Convert the Story to an Epic (using both New Nav and Old Nav).
4. Observe the handling of the existing Subtasks.

Desired Results

• When converting a Story with Subtasks to an Epic, the user should receive a prompt or warning indicating that Epics are not intended to have Subtasks.

• The system should require the user to either:
  • Convert the Subtasks to a supported issue type (e.g., Task or Story), or
  • Remove/reassign the Subtasks before completing the conversion.

Expected Results

• No prompt or warning is shown.
• The Subtasks are simply moved into the 'Child Work Items' section of the Epic.
• This results in an Epic containing Subtasks.

Workaround 

A Jira Automation rule can be set up to monitor when a Sub-task’s parent is set to an Epic. If this happens, the rule automatically reverts the parent to its previous value, keeping the hierarchy clean and consistent. The user can import the provided automation rule JSON directly into their Jira Cloud instance. Attaching the JSON of automation.