Go to Options > Preferences > RealTracks and check if the Custom Folder points to the location of your external drive that holds the RealTracks.

Do the same for Options > Preferences > RealDrums


BIAB & RB2026 Win.(Audiophile), Windows 10 Professional & Windows 11, Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors