Judgment of the General Court (Ninth Chamber) of 27 September 2023.#Fundación Imdea Materiales v European Commission.#Arbitration clause – Seventh Framework Programme for research, technological development and demonstration activities (2007-2013) – Grant agreement – ‘Compound Semiconductors for 3D integration’ project – Repayment of sums paid – Payment of damages – OLAF investigation report – Debit notes – Eligible costs – Reality of the costs – Reliability of timesheets – Alternative evidence – Proportionality.#Case T-765/21.