Given the following request

PATCH http://localhost/mantis/api/rest/issues/{{id}}
Authorization: {{token}}
Content-Type: application/json

{
  "target_version": {
    "name": "xxx"
  }
}

The API responds with 400 BAD REQUEST

{
  "message": "Version 'xxx' does not exist in project 'Test Project'.",
  "code": 29,
  "localized": "Invalid value for 'version'"
                                   ^ this should be 'target_version'
}