"The backup disk image could not be mounted" - What do I do?

I'm having the same problem on all 5 of my Macs in my house

Same problem here. Fine for months until yesterday. Only change I made was the upgrade to 10.5.8. Wonder if it could be that. Have genius bar appt for Sunday and will take time capsule in, but doubtful that they can do much as I didn't change the time capsule.

Welcome to the discussions!

The connection between your Time Capsule and your computer has has been lost. Try these steps:

Open System Preferences and open Sharing. Make sure that your computer name appears. Try to eliminate any apostrophes or other punctuation marks and limit to 27 characters or less including spaces.

Open AirPort Utility and click on Manual Setup. Click the Time Capsule tab below the icons. Make sure that your Time Capsule name appears. Use the same guidelines as above.

Also while in AirPort Utility, click the Disks icon, then click the File Sharing tab just below. Make sure there is a check mark next to "Enable File Sharing"

Click in an open area of your desktop to show the Finder menus at the top of the screen. Click on Finder and then click on Preferences and then the General tab. Under the heading of "show these items on the desktop", make sure there is a check mark next to "Connected Servers"

Power down the Time Capsule and wait a few moments, then power it back up.

Now click System Preferences and Time Machine. Choose Change Disk and click your Time Capsule to highlight it and then click Use For Backups.

A step above or a combination of steps will usually get backups going again.

Any help?

This has worked on my MBP, but be aware it has lost it's original back up and has started backing up again.

The iMac appears to have just started again after restarting the Time Capsule, will find out later on if either were successful.

Cheers
Jono

Unless you have made a major change on your MBP, like a new main board replacement, etc. this should not cause Time Machine to start a new backup.


I wonder if your recent switch to 10.5.8 may have something to do with this.

You are most welcome! Glad you got things going again.

Nope. Tried the full routine you suggest. Upon trying again, I got both the "disk image could be mounted error" and also an alert saying the drive was available on in read only mode and suggesting an immediate backup.

May be a hardware problem. Off to Genius Bar tomorrow.

I tried the steps above with full hopes and...nothing. Time Capsule was humming along great when it suddenly decided to stop backing up. Second time this has happened. First time, I had to wipe out the backup and start over as it would still backup my laptop, but not the desktop. The message I am getting now is:

"Time Machine Error: Unable to complete backup. An error occurred while copying files to the backup volume".

Any help would be GREATLY appreciated!

I'm having the same problem as all of you. Could this be a bug since we're all experiencing it at the same time? I erased my Time Capsule and am trying to start from scratch. I'll report back here if everything works.

Also, I don't believe it's a 10.5.8 bug because mine started screwing up when I was still on 10.5.7 In fact, this is what prompted me to update to 10.5.8 because I thought it might fix the issue to no avail.

Did you try deleting the com.Apple.TimeMachine.plist file?

Hard Drive > Library > Preferences

Restart your computer and reset Time Machine. Not a cure all, but sometimes helps when error messages start appearing.

Well I used airport utility to erase the whole disk. Then I started a new Time Machine backup and it was stuck in preparing for forever. I finally ended the backup and ran it through disk utility. Disk utility found errors on the drive so I decided to erase the disk again through airport utility, but this time do a secure 1 pass erase instead of a quick format. Hopefully this will get rid of any errors on the disk.

Just did this and it didn't work:

Moved plist file to the trash.
Shut down machine.
Reset Time Capsule (by unplugging...waiting a minute...and replugging it in)
Reconfigured Time Capsule setup.
Started a backup...heard everything boot up...and backup failed.

😟

Maybe our hard drives are failing? Mine is half way through a full format.

Although this post is marked as answered......for those of you still getting the error about the disk image try this (it has worked for me)....

Go to Time Machine Preferences, select change backup disk, choose none and then stop backing up. Then open up Keychain Access and delete all references to your Time Capsule from both the login and system keychains (you can keep the network password items). Might as well delete the com.apple.timemachine.plist at this point as well. Restart, then back to Time Machine preferences, choose the backup disk again (you'll be prompted for the base station password) and start backing up.

For those of you that are getting read only errors, errors copying files or stuck at preparing, those are different issues best addressed with another post. My quick answers (in order) would be, delete your backup and start again, check Console, search for "backupd" and see if you can find a particular file that it's stuck on and exclude it from your backups and finally, wait.

hope this helps