Photoshop 27.6.0 does not recognize external APFS disk as scratch disk on macOS Tahoe 26.3.1

Question

Since updating to Photoshop 27.6.0, external APFS disks no longer appear in Preferences > Scratch Disks. The disk is properly formatted, correctly mounted, and visible in Finder and Disk Utility, but Photoshop does not list it as an available scratch disk option. This worked correctly with previous versions of Photoshop on the same system. Tested on macOS Tahoe 26.3.1 with a 256 GB external SSK SSD formatted as APFS. Reformatting the disk as HFS+ (Mac OS Extended Journaled) via Terminal makes the disk visible in Photoshop scratch disk preferences, but macOS Tahoe unmounts HFS+ external volumes intermittently, making it an unviable workaround.

D Fosse · Answer

First thing to try is always to reset preferences.

Preferences/settings are vulnerable to corruption because they are rewritten on every application exit, as opposed to read-only program files.

The safest and most complete way is to move the whole Adobe Photoshop 2026 Settings folder to your desktop, so that a new one can be built. This returns the application to clean, out-of-the-box factory state.

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded