Aperture locked up when duplicating an image. I had to force quit, when I restarted I rebuilt the database. 5,300 images showed up as recovered.
Turns out they were all thumbnails for iCloud shares, but they’d lost connection to iCloud. When I deleted them I found most of my iCloud share streams were empty.
I believe I have my images, but it is sad to lose the relationship to the shares. Aperture is no longer supported by Apple of course. I’m running El Capitan, for what that’s worth.
Backups are no help of course. Even if I could recover the relationship to photos shared in iCloud I’d lose other work.
/Users/jfaughnan/Library/Application Support/iLifeAssetManagement/assets/pub has 7.5GB of files holding 2,634 items including some photo stream temp files. It’s not clear if this can be deleted, but it may be Aperture doesn’t use it…