OK. I think I might know what the "cleaning function" is.

You wrote your BIAB version is many years old. Perhaps the program is recommending you can delete what is called the +/- files. In the early days of RealTracks, every RealTrack had other copies pitched above and below, to accommodate pitch shifts. This isn't needed now, since about three years ago (guessing here) PG Music started using the Elastique pitch stretching algorithm (which is much better). On a reasonably fast PC, you could then erase the +/- files. PG Music didn't automatically erase them, though, because on a slower PC, BIAB worked better if they were still there. You can still see this in the form of a checkbox in Preferences, RealTracks.

The net effect of the change was that RealTracks now took up about 1/3 the space on the hard drive that they formerly did. Moore's Law definitely does not apply here.

Does any of what I've said sound like the instruction you are getting? If you are unsure, I recommend you get on Live Chat with PG Music Support and explain your situation to them.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.