Does a clean Europol result guarantee I will not face problems with individual EU member states?

No. Europol is an intelligence hub, but each EU member state maintains independent national law enforcement databases — SIS II alerts, national police records, prosecutorial files — that are not fully replicated in Europol’s systems. A negative Europol result confirms no centrally-held EU-level data, but it does not preclude the existence of national records in Germany’s INPOL, France’s TAJ, or Spain’s PERPOL systems. For comprehensive data hygiene, parallel access requests to relevant national authorities and SIS II are advisable, particularly if you have specific country exposure through residence, business activity, or prior investigations.