As an User I get an error message reporting the reason why the export to cucumber failed (when the link between the Story and the Tests is not the correct one)

As an User I get an error message reporting the reason why the export to cucumber failed. Because it can be difficult to find the source of the problem when the export fails.

When the link between the Story issue and the Test issue is not the correct one, i.e, when the Story is not tested by the Test, an internal server error 500 is displayed via REST API and an "error exporting cucumber feature" is displayed via UI.