Invalid Checksum when burning Lion to disc?

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Level 1

11 points

Invalid Checksum when burning Lion to disc?

I've tried downloading OSX Lion from the App Store about 4 times one of them was while it was hard wired directly to the modem using Verizon Fios service. I've tried creating a thumb drive without sucess several times and keep getting a "Restore Failure, invalid argument" error message.

The dvd (dvd-r) I was trying to burn I get a "invalid checksum" error message and won't burn also.

Does anyone know what I can do to get myself a burned copy of Lion so I can slick my hard drive and start all over?

Please help as something so simple has become such a nightmare!!!

iPad 2, iOS 5.0.1

Posted on May 10, 2012 2:03 PM

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Answer 1

May 10, 2012 2:28 PM in response to todd1010

The options here are to either try downloading the installer again (recommended) or set your disc burning program to ignore the checksum warnings and burn the disc anyway (not recommended).

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Answer 2

todd1010 Author

Level 1

11 points

May 10, 2012 2:32 PM in response to Topher Kessler

I'm using the Apple Disc Utility to burn it and not sure how to ignore the checksum warnings, however as you said I don't believe that is something I want to do.

I will try downloading it again. Is there a way to verify the install once it's been downloaded to make sure it's valid?

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Answer 3

May 10, 2012 2:36 PM in response to todd1010

You can verify it by choosing "Verify..." from the "Images" menu in Disk Utility. In Disk Utility you can disable checksum verification in the program's preferences settings. While in many cases a faulty checksum might be as simple as a metadata change for the file or its contents, or the developer forgetting to update the disk image's checksum after such a change, it could be from a more serious change that could result in corrupted files. This is why it's better to check the image and ensure its data organization is as the developer intended it to be received.

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Answer 4

todd1010 Author

Level 1

11 points

May 10, 2012 2:42 PM in response to Topher Kessler

Disc Utility said it was:

Unable to verify "InstallESD.dmg." (calculated CRC32 $D0C5F48C, expected CRC32 $D7975722)

Is this something wrong with the original download. So how can I assure I'm getting a valid download from the App Store? This is where I've already downloaded it several times already.

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Answer 5

Jun 5, 2012 11:00 AM in response to todd1010

I found an answer and am implementing same at this moment:

https://discussions.apple.com/thread/3941004?answerId=18542854022#18542854022

Use CCC

🙂

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