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macrumors newbie
Original poster
Aug 14, 2009
For the fast few weeks every .dmg file I download shows up in the Finder and in Disk Utility as corrupted. This includes downloads of manuals, application updaters, etc, including anything downloaded by Apple's Software Update.

Any suggestions?


macrumors 68040
Mar 3, 2008
One thing that comes to mind is your hard disk might be on its way out. It could be that these files are being written to areas that have physical errors and when you read back the dmg file it is corrupted. Because this is a possibility, I suggest you copy important files to an external usb drive so that if your hard drive does take a dump you don't lose absolutely everything. Another possibility is that disk utility itself has become corrupted. Try using disk utility to check a cdrom. If it thinks the cdrom is corrupted then disk utility is a likely culprit. What happens if you try to mount one of the "damaged" dmg files (by double-clicking)? Does it mount or do you get some sort of error. Do you have any dmg files lying around from before this started happening? What happens when you try to mount them or examine them with disk utility. To me it seems that even the lousiest net connection in history couldn't cause each and every dmg you download to be corrupted so that's why I'm focusing on issues that could be caused by your Mac, such as a sick (and dying) hard drive.


macrumors 6502a
Aug 26, 2007
Interestingly, I noticed that yesterday on a machine running 10.5.6. I downloaded a number of updates including the 10.5.8 combo using software update and when the update ran, it failed part way through and reported that there was a problem because the image could not be read or something to that effect.

I ran diskutil on my disk and found there was corruption. I rebooted using the install disks and ran a disk repair. That cleared up the corruption and I seem to be ok now.

The experience was a little frightful.


macrumors 601
Mar 4, 2005
.. London ..
I had a similar issue and my HD failed very soon after. Treat your HD with extreme suspicion, back up important files NOW and start planning what you're gonna replace it with.

HD failure is no big deal as long as you're ready for it. It can be scary when a HD 'sort of works' but you don't know why.
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