You have to tell BIAB where that additional drive is so it can find the Real Tracks and Real Drums. You do that in the Options - Preferences - Realtracks.

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BIAB – 2025, Reaper (current), i7-12700F Processor, 32GB DDR4-3200MHz RAM, 1TB WD Black NVMe SSD, 2TB WDC Blue SSD, 1TB WD Blue, 2 TB SK NVMe, 6 TB External, Motu Audio Express 6x6