We are investigating an intermittent package installation failure on macOS Tahoe 26.5 and are trying to understand the conditions under which PackageKit may return the following errors during an upgrade installation: PKInstallErrorDomain Code=120 NSPOSIXErrorDomain Code=1 ("Operation not permitted") The package successfully passes validation and authorization, and pre-install scripts complete successfully. The failure occurs during the final PackageKit commit phase when PackageKit attempts to move/relink content from the installer sandbox to the destination volume. Relevant log snippets: PackageKit: Shoving /Root to / Error relinking file (primary): .../Contents/_CodeSignature/CodeResources failed _relinkFile(...) Operation not permitted PackageKit: Install Failed: Error Domain=PKInstallErrorDomain Code=120 NSUnderlyingError: Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted" The issue is intermittent and only affects a subset of systems. The same package installs successfully on many machines running the same macOS version. Has anyone encountered similar _relinkFile / CodeResources failures during package upgrades? In particular, we are interested in understanding: Common causes of NSPOSIXErrorDomain Code=1 during PackageKit relink operations. Whether existing signed application bundle metadata (CodeResources) can cause relink failures during upgrades. Any Installer or PackageKit changes in recent Tahoe releases that could affect bundle replacement during package installation. Any insights would be appreciated.

Hello Team, We’ve recently started receiving reports from our customer base (Trellix) regarding issues with Full Disk Access (FDA) for Trellix binaries on macOS devices running Tahoe 26.1 (released on November 3, 2025). The issue occurs when users attempt to add Trellix CLI binaries under FDA to grant the required permissions; the binaries fail to appear under the FDA settings, even after selection. Upon further investigation, this appears to be a macOS 26.1–specific issue and not observed in earlier versions. Similar reports have been noted across various forums, indicating that the issue affects multiple binaries, not just Trellix: Some of the discussions on the same issue I see online. https://developer.apple.com/forums/thread/806187 https://developer.apple.com/forums/thread/806156 https://forum.logik.tv/t/macos-26-1-installation-issue-wait-before-updating/13761 https://www.reddit.com/r/MacOS/comments/1os1ph3/cant_add_anything_to_privacy_security_full_disk/ I have also logged FB21009024 for the same. We would like to understand when we can expect this to be fixed, since the issue persists even in 26.2 Beta and also whether the workaround of dragging and dropping the binaries can still be suggested?