How to resolve “iTunes could not back up the iPhone because the backup was corrupt”?

Question

When I try to sync my iPhone with my computer, I get the following message:

iTunes could not back up the iPhone "iPhone Name" because the backup was corrupt or not compatible with the iPhone.

Delete the backup for this iPhone, then try again.

Yet, here is no option to delete the backup. Where are backups stored / how can I delete the backup?

This is iTunes version 10.5.3 running under Mac OS X 10.6.8.

Answer 1

From within iTunes navigate to the menu iTunes > Preferences > Devices. Select the backup file, then hit the delete button:

Answer 2

I had the same problem, no idea where it came from. I had a jailbroken iPhone 3G and switched to a non-jailbroken iPhone 4, i.e. I transferred the backup to the new phone, which worked. Some time later, however, I got that error message. I tried the solution above, I even deleted all backups, even the ones not related to that phone, but the error persisted.

I found a solution in a comment to the thread iPhone could not backup because backup file was corrupt or not compatible, fix, more details in a following comment. Here’s what to do, summarized:

(This is a solution for Windows (7), which doesn’t apply to the OP, but his problem seems to have been solved already at any rate.)

• Close iTunes
• Make sure your Explorer displays hidden files
• Go to C:\Users\username\AppData\Roaming\Apple Computers\MobileSync\backup
• Delete everything there (or move it somewhere else, to be on the safe side)

And done. In my case, I deleted two folders with long, cryptic, alphanumeric names, one empty, the other over 1GB in size. When I opened iTunes again, I could create a brand new backup without any errors.