At CYME, we have been using Aperture for the past two years very extensively in our tests.

Last week, Aperture stopped being usable on Catalina (macOS 10.15.7), after it started to render all previews and thumbnails of an open catalog as black images.

We have not found the cause for it. We reinstalled, cleaned the preferences, reapplied Retroactive, etc... It does not help. It happens on existing catalogs but also on newly imported images in a brand new catalog. All previews and thumbnails are black (confirmed when looking into the catalog itself in the Finder).

We cannot tell if it is linked to the mac itself, or is an issues that could affect other users. Our M1 MacMini running BigSur does not seem to have the issue.

I currently wonder if a macOS update has not been applied with the above side effect.

If any of you has the same issue on Catalina, we'd love to hear from you.