Workshop “forget” engine block holder”

Hello everyone! In my current 120,000er inspection, my dealer sees that a screw is missing for fixing the engine block: Diagnosis: Thread no longer available! Repair of the thread: ~95,00 € Bloss, how can one find the person responsible? Renault Germany says that only the dealer is responsible for repairs. Does anyone know which of the following procedures could have been the removal of this screw?: – alternator (replaced in Florence) – ignition coil (replaced in Bruneck/South Tyrol) – search for electronic damage (in Bruneck/South Tyrol) – otherwise the usual maintenance intervals (after possibility at home in Mainz, who also discovered the nail, 1. at 30,000 in Poznań/Poland, 90,000 in Innsbruck/Austria) I guess on the Florentiner with the light machine in September (last major intervention before the inspection) If someone had a tip before I look past there….? Ciao!