Case C-743/18: Judgment of the Court (Third Chamber) of 1 October 2020 (request for a preliminary ruling from the Rēzeknes tiesa — Latvia) — LSEZ SIA ‘Elme Messer Metalurgs’ v Latvijas Investīciju un attīstības aģentūra (Reference for a preliminary ruling — Structural Funds — European Regional Development Fund (ERDF) — Regulation (EC) No 1083/2006 — Article 2(7) — Concept of ‘irregularity’ — Infringement of a provision of EU law resulting from an act or omission on the part of an economic operator — Prejudice caused to the general budget of the European Union — Insolvency of the beneficiary’s sole business partner)