I've been in contact with NI support for the past few weeks about this [latest ticket #4087509] but haven't heard back for a few days. It's an urgent issue as I am unable to do further work on my clients projects.
Issue: While I was working on a project in Ableton using Massive X, Massive X's presets suddenly disappeared. Later on, I realized the presets for Battery 4 and Kontakt 7 were also missing. The issue with Battery 4 and Kontakt 7 were able to be fixed by re-navigating to the proper preset directory. But Massive X presets remain missing. This is the case in Ableton and in LPX.
What I've done: I checked that all NI apps and DAWs have full disk access. Massive X is fully updated. Tried reinstalling the factory presets. Tried reverting to Native Access 1, Battery 4 has now been causing Ableton to crash. Re-upgrading to NA2 hasn't fixed this crashing issue, or the Massive X preset issue.
NI support suggests I make a new empty macOS user account and migrate everything over to that. But this is not feasible, it would break many of my other projects and would take (at least) several days to do. And it seems extreme given that everything else on my computer works fine except NI's software, Massive X.
What other solutions are there? I am on Big Sur 11.7.1. Would updating to Sonoma fix this? What about reinstalling everything NI?