DMGs with license agreement fail to mount onto some Sonoma installations

Some of my users report a failure during mounting a DMG onto Sonoma created by DropDMG.

You find the complete thread here:

Any idea?

P.S: I use the latest DropDMG release version.

There’s a bug in macOS 14.0 that can cause this error (“The disk image couldn’t be opened. The operation couldn’t be completed. Permission denied.”) when mounting a disk image (FB13165607). It seems to only affect disk images that have license agreements and quarantine flags, and even then it does not happen on all Macs. It affects both disk images created with DropDMG and other tools. Some known workarounds:

  • Temporarily stop using a license agreement
  • Remove the xattr from the .dmg file after download
  • Download the disk image using a tool (e.g. curl) that does not add the quarantine attribute
  • Give the DiskImageMounter process Full Disk Access
  • Update to macOS 14.1 (beta), which seems to fix this bug