Updated Mac OS and Lightroom can't find photos

Moderator or Admin

Can you edit this new members description in this post. IOS should read MACOS, otherwise this would not belong in LrC, as it would reference to Mobile.

be aware that current releases of Lightroom Classic are not yet supported on Sonoma. We probably need the next version of Classic released to get full compatibility: https://helpx.adobe.com/lightroom-classic/help/lightroom-classic-and-macos-sonoma.html

That said, if you are using an external hard disk, you might need to make sure that Lightroom has full disk access (System Settings->Privacy and Security->Full disk access: add Classic) and that the catalog is referring to the correct location. Typically you just have to do a update folder location (right or control click on the top level folder in the Classic sidebar) to reconnect it to the correct location on the external disk.