FCPX project thumbnails *still* missing (2025)

For some reason the previous thread about this was closed, despite the problem having not been solved.

https://discussions.apple.com/thread/254900229

I'm using FCPX 10.7 under Ventura 13.6 0 - but this irritating problem has been present across every single FCPX version I have ever used. Why...?

I have tried deleting my cache (render files including thumbnail data) and restarting etc. Makes no difference.

My cache is always stored in the library. My library is always on an external SSD.

Joema (there's a name from the past - from the old fcp.co days before that website, without due warning just disappeared, with users having no time to archive useful threads) reported in the thread linked above:

[I formerly thought the thumbnails for the project icon were taken from the thumbnail cache inside the library in /EventName/Render Files/Thumbnail Media. That is where the timeline thumbnails come from and I think for filmstrip clips in the browser.

However I did some brief tests that imply the project thumbnail is not taken from that cache.

I can add a clip to a new project, and the project thumbnail will remain black. If I click on a few things or switch several times between filmstrip view and detail view, it will fill in. Using the terminal command fs_usage to capture all I/O FCP is doing, it does not access the cache thumbnails when that happens. It does getattrlist calls on the original media files but does not read or write I/O. So it is apparently an in-memory state change.

When the project thumbnail fills in, these are the sequence of FCP calls. the 'switchDisplayViews' method is when it switches back from list view to filmstrip view. It checks to restore the previous filmstrip view selection, then calls the 'reloadData' method. That call may be what fills in the project thumbnail.

-[FFOrganizerFilmstripModule switchDisplayViews:]

-[FFOrganizerFilmstripViewController matchSelectionToPreviousModeSelection:]

-[FFOrganizerFilmstripView activeSelectionDidChange]

-[FFOrganizerFilmstripView reloadData]

It's possible upon initially adding the clip to the project, there is a code path which fails to populate the thumbnail. However I don't know why some users report it as widespread and consistent behavior.]

It confounds that after all these years, FCPX still hasn't fixed this issue. These sorts of glitches make the application feel unstable and unreliable and I wish there was something we could do to address this.

Has anyone found a solution?

Please don't advise me to upgrade anything. There are very good reasons (for *me*) that I use my current configuration and upgrading, changing versions etc is *not* a simple fix-all when I rely upon a range of paid for applications that will be affected by changing my OS etc. Again, this thumbnail thing is certainly not a new issue anyway and appears to be quite a universally experienced problem.