Just seeing this now but thought I would add that rather than uninstalling, reinstalling of various versions of Halion Sonic, or renaming databases as I saw in another thread, that what worked for me (after finding some āmissing audioā after moving all my Steinberg libraries to a new location that initially seemed all was good) that I right clicked on the problematic instruments (a few pianos in this case) and saw they were either Raven or Eagle ones. I just went to the folder I had all the Halion library sounds in and double clicked on the Raven and Eagles ones (there were a couple or several for each) - some said they were installed but some did refresh. Went back and tried the sounds in HS and all good. Hope this helps someone and saves a bunch of possibly unneeded uninstalling/reinstalling.