This error is caused by the issue link type of "Relates" not existing in JIRA. The issue link type of "Relates" is a default link type in JIRA but due to customization could potentially be renamed or removed by a JIRA administrator.
Aha! relies on this issue link type when passing the Aha! Feature -> Requirement relationship to two JIRA issues that do not have a natural parent-child relationship. An example of this would be if you map Aha! Features and Requirements both to the same issue type, such as a User Story, in JIRA. In this case, both the Feature and the Requirement would be created in JIRA as unique user stories linked together through the "Relates" issue link.
To fix this issue:
- In JIRA go to Settings -> System -> Issue Linking.
- Check for the Issue link named "Relates" which typically has the outward description value of "relates to".
- The integration works off of the Name value which must match "Relates".
- If the link type does not exist, create a new link type and ensure the Name value is "Relates".
- If the link type exists, but has some sort of typo where the name is not spelled exactly "Relates", edit the issue link accordingly.