I use Apple Time Machine to backup my MacBook to a Mac Pro over my LAN/WiFi network using the Snow Leopard AFP time machine hack. Recently the MacBook’s hard disk totally failed and I needed to mount the disk image on the Mac Pro to pull a few critical files off immediately. The sparsebundle appeared in Finder as a folder with a small red minus sign, meaning my user account didn’t have permission to access it.
When I attempted to open the backup image I received an error stating “You do not have permission to open the document MacBook”. Note: “MacBook” was the name of the system Time Machine was backing up.
After approximately an hour of experimentation and research, I found the fix:
Open Terminal in Applications/System Utilities.
“cd” to the folder where your sparsebundle file resides.
(i.e. cd “/Volumes/Media/Time Machine”)
sudo chown -R `id -un`:`id -gn` MyTimeMachineBackup.sparsebundle
Enter your password.
Note the “`” quotes above are the slant-quote on your tilde key
on the top left of your Apple keyboard below the “esc” key.
You should now be able to access and mount the image.