Issue Summary

Branch for Stories (or other issues in Epic) fails if sub-tasks are disables

Steps to Reproduce

1. Disable sub-tasks
2. Create a rule that runs on an Epic event and has a branch for Stories (or other issues in Epic)
3. Trigger the rule and it will return an error containing "Field 'parent' does not exist or you do not have permission to view it"

Expected Results

Run is executed

Actual Results

An error is logged related to parent field

Workaround

Enable sub-tasks and delete any issue type with the type sub-task