If a Jira site export contains corrupted data it causes the complete site import to fail.
This problem manifests itself under various circumstances: (see internal notes in the first comment)
- Generate an export file from a jira instance (server or cloud)
- edit the xml export file to create one piece of data to be "orphaned" (for example, remove a <project entity, but leave the <issues)
The import complete successfully. The orphaned entities are ignored.
The import fails with an unhelpful error message such as
Manually edit the XML export file to remove the orphaned entities.