Equity requirement - business + real estate

I'm looking at buying a business and its underlying real estate. My plan for the equity injection requirement was to bring 5% cash to the table and have the seller carry a 5% note on full standby for the life of the loan. However, I had a lender tell me that this isn't possible when a business and real estate are combined in the same loan, which is news to me. Can anyone else opine on this?