

If you’re on Mac OS 10.14 (Mojave) or earlier, PSB Quick Look is required for Finder to display PSB previews and thumbnails. While PSD files are limited to a maximum of 30K x 30K pixels and a total of 2 gigabytes, PSB files can be as large as 300K x 300K pixels, with no limit on total byte size. With higher-resolution cameras, panoramas, HDR, and sophisticated multi-layer editing, more and more Photoshop users are adopting the PSB file format.

And that won't work because one day you may get a new Mac and that will only run the current version of macOS and only support 64-bit apps. Your only other option is to stay behind in 2020 with Mojave forever. You can simply get the new version of Lightroom. It is time to move on from old apps that are still 32-bit. This change started 6+ years ago and Catalina came out more than 2 years ago. You can select the app in the Applications folder and use File, Get Info to see if it is 32-bit or 64-bit. If your "legacy" version of Lightroom is so old that it is 32-bit, then no, it won't run in Catalina or beyond.

(Earlier versions of macOS supported both 32-bit and 64-bit). Developers were told of this change a long time ago, and unless the developer had abandoned the app or procrastinated a great deal, they had 64-bit apps out long before Catalina. Before that macOS still supported running older 32-bit apps. "Legacy" can mean a lot of things.īasically, starting with Catalina you can only run apps compiled for 64-bit processors. Impossible for me to say without knowing the details.
