I would not have noticed this issue in macOS 15 because I was not changing the icon, and it had been previously cached. With Mac OS 26 and the new glass icons I decided to make an icon upgrade to an App and its associated Screen Saver, that’s when I first became aware of the issue. So I suppose I’m reporting a regression, or simply “hey it’s broke, I want some glass”. The Screen Saver docs do not mention the System Setting thumbnail, but it seems I learned to include two thumbnail files: thumbnail.png 90x58 px thumbnail@2x.png 180x116 px The saver installer then takes these two files and creates thumbnail.tiff, a single file that includes these two PNGs (never knew that was possible!). When I modified the two PNGs there was no change in appearance in the System Settings thumbnail. So the installer was using a cached thumbnail, but I haven’t located where it is. For the test saver in FB21094920 I was never able to set its icon/thumbnail, and it used the blue swirl (I assume) because
Topic:
App & System Services
SubTopic:
General
Tags: