Aliases and Bookmarks on macOS
A question was recently asked about the macOS Open Recent menu, and menu selections no longer automatically mounting file containing disk images.
The question evoked long archived memories of dealing with aliases and some of their versatility and user focus.
I contributed the answer below.
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macOS 26.1
It appears macOS changed the URL bookmarks format in macOS 26.1. This change could explain the recent change in behaviour you have noted.
From Archaeology v1.5’s release history:
Restored the ability to decode recently-created URL Bookmarks. Apple changed this binary format in macOS 26.1, macOS 15.7.2 and macOS 14.8.2, and that would cause the decode to fail. Archaeology can now decode the new bookmarks, and will show the new (usually empty) Team ID therein.
Aliases and Bookmarks on macOS
The behaviour you are seeing suggests the previously working Open Recent links that mounted a disk image (.dmg, .iso, …) involved an alias:
The Alias Manager can track files and directories across volumes. If the target of an alias record is on an unmounted AppleShare volume, the Alias Manager automatically mounts the volume when it resolves the alias. If the target object is on an unmounted ejectable volume, the Alias Manager prompts the user to insert the volume.
On macOS, the deprecated Alias Manager supports automatically mounting target volumes when resolving an alias.
macOS’s replacement for aliases is Bookmarks. Bookmarks appear to have dropped this mounting ability. Bookmarks instead are focused on sandboxing and security; rather than resolving potentially moved files and unmounted target volumes.
Software can continue to create aliases and thus continue to support automatic mounting but newer software will migrate to Bookmarks and be unlikely to support this ability.
For most applications, the Open Recent menu is handled by macOS. How macOS tracks the Open Recent files will change between versions of the operating system. macOS may also change behaviour depending on the application software involved.
I originally published this answer on Ask Different.