Replace boot.firm with the one from the latest (9.1) release. The only way to get this message I know, is trying to start Luma v7.1 with a newer version of B9S. If the error persists with a new boot.firm there may be a problem with your SD (wrong filesystem/defect/fake) and the console uses an old firm file directly from the NAND.
Reformat the SD to FAT32, 32kb cluster size, if bigger than 32GB and using Windows with guiformat.