The issue is that for a universe of 25000+ ISINs (mostly Certificates listed on EuroTLX/SeDeX), the rd.get_data() function returns an Empty DataFrame when requesting fundamental fields like TR.BarrierLevel, TR.StrikePrice, or TR.ExpiryDate. However, market data fields (like TR.CLOSEPRICE) work fine for the same ISINs. It seems my App Key lacks the Entitlements for 'Reference Data' on the 'Structured Products' asset class, or there is a mapping issue between ISINs and RICs in the rd.Library for these specific venues. Can you verify if my profile has the 'Fundamental & Reference Data' permissions enabled for Structured Products?"