I encounter this message: 
“This copy of the Install OS X [OS X Name] application can’t be verified. It may have been corrupted or tampered with during downloading.”

Due to an expiration of OS X App Store certificates, installers of OS X downloaded prior to February 14th of 2016  can’t be used to re-install OS X without encoutering this error. This is not a problem with DiskMaker X per se, but with the installers provided by Apple.

There are three ways to avoid this problem :

  • If you did not erase your Mac and its OS is still working fine, reboot on its hard drive, open System Preferences > Date and Time, uncheck Automatically set up date and time and set the date 13th of February 2016, then disconnect from network and reboot;
  • If you don’t have an OS installed anymore, reboot on your OS X install disk built with DiskMaker X, open Terminal and type:
date 1010101015

Which will set the date and time on the 10th of October 2015 at 10:10 (it’s just easier for me to remember, but any date in the five last years or so should work).

The last solution (and the best) is to re-download the OS X installers from the App Store. Which is OK for El Capitan if you currently run it, but what if you want to re-download older OS? Sadly, Apple does not allow to re-download say, Lion or Mountain Lion, if your Mac already runs a more recent version of  OS X (which sucks REALLY badly). There are two solutions here :

  • Re-install at least Lion on a drive, boot on it, open App Store and re-download the apps…
  • If your Mac does not support older versions of OS X to reboot on, use a virtual machine with Parallels Desktop or VMWare Fusion to re-install Lion in it, then re-download the installers from Lion’s App Store.

Also, beware that if you have OS X installers on any volume mounted on your Mac: the first copy of the installer the App Store will find will be updated if you decide to download a new version, wherever this copy of the installer is on your boot drive or not.

I bought a recent Mac, I built a disk with DiskMaker X but I can’t boot on it !

This one is tricky to explain. Please take a drink first.

When a new model of Mac is available, it usually ships with an “almost” standard version of OS X. I wrote “almost” as it is a special build of OS X, designed only for this specific kind of new Mac.

The problem is quite well explained here:


The following points are especially important:

  1. Some Macs may include a slightly later build version (but same numbered version) of Mac OS X on the Install or Restore discs than was preinstalled on your computer.
  2. Do not use a Mac OS X version earlier than the one included with the computer.
  3. Retail copies of Mac OS X may not always work properly with new Macs. Even if the retail version has been updated via Software Update to a later version of Mac OS X than originally came with a Mac, you may have unexpected issues. Always confirm operating system functionality by using the install disc that shipped with your particular Mac.

So ? If you get a new Mac, you won’t be able to use the installer downloaded from the App Store. The only solution to fully re-install your OS is to use OS X Internet Recovery.

However, there is also another way.

Basically: please be patient. When Apple will release a new version of OS X (say, 10.9.2), you will be able to download from the App Store the full OS X 10.9.2 installer which will provide a new “universal” build of OS X, allowing full install and allowing to build a new boot disk with DiskMaker X on your brand new Mac.

And please, wait before buying a new Mac the next time.

I stumble on a message: “An error occured: -2753. The variable OSX_App is not defined”

This happens if you use the 10.9.x DMG file instead of the full OS X Mavericks Installer app. It just won’t work. Please use the installer app.

When installing, I stumble on this error message: “This copy of the Install OS X Mavericks application can’t be verified. It may have been corrupted or tampered with during downloading.”

Known bug from Apple, your Mac’s clock is set to a wrong date/time. Check this KB article for a solution.

An error -1782 occurs after DiskMaker X copies files: “Can’t get disk “OS X Mountain Lion Install Disk” or similar.

Bug in version 3.0.1, corrected with 3.0.2 and later. The USB boot disk will work however.

An “Error -10660” happens in the building process.

Run DiskMaker X in an admin session (not a standard user session). It should work much better.

I built a disk with Lion DiskMaker 3.0 but can’t boot on it! It does not appear at startup or in the Startup disk Preference.

This has been fixed with DiskMaker X 3.0.1 and later. Give it a try. The (funny) explaination for this bug is here.

Can DiskMaker X build a drive with different versions of OS X ? Say, one partition with Lion Install, another one with Mountain Lion, and another one with Mavericks ?

Sure! Just format your removable drive with a few 8 GB partitions, and launch DiskMaker X. Then choose the “another kind of disk” option and select the right volume each time.

I can’t use DiskMaker X with Mac OS X 10.6.x if I try to use it with my Mavericks installer!

Because of a bug (or a feature?) in Apple’s built-in command createinstallmedia with 10.6.X, DiskMaker X is not compatible with versions of OS X prior to 10.7. I’m working on a fix, but it may take some time to make it available as it means using another completely different method. Check the blog regularly for updates.

I get an error: “The domain/default pair of (/Volumes/OS X Base System/System/Library/CoreServices/SystemVersion, Production Version) does not exist.”

This happens mostly because your OS X Install App is damaged. To check if this theory is correct :

  1. Right-click or Ctrl+Cllick on the  Installer OS X Mavericks application;
  2. Go to Contents/SharedSupport;
  3. Double-click InstallESD.dmg.

If an error message appears, you’ll have to download again the Installer app from the App Store. If it mounts properly, get in touch with me.

Note that Lion DiskMaker 3.0.1 should better handle this case.

I keep encountering an ASObjC Runner error (Error -43. File ASObjC Runner wasn’t found)

This one is quite tricky. It’s a bug which happens randomly with Lion DiskMaker and has no real explaination, except some coding error.

The only way I found that could remove the problem would be to :

  • Use Activity Monitor (in /Applicationsl/Utilities) to quit any instance of ASObjC Runner ;
  • Reboot your Mac ;
  • Check again if  ASObjC Runner is still running in the Activity Monitor ;
  • Then launch Lion DiskMaker again and try to build your disk.

Also sometimes, using a different, clean session may help.

If you have any insight in this problem, please get in touch with me.

After choosing the OS, Lion DiskMaker seems to hang.

This is related to some issues with Spotlight. To workaround this, open Terminal and type :

killall -9 mdfind

then type Enter key. Lion DiskMaker should resume automatically.

I am told I have no copy of OS X Install available.

The OS X Install application is automatically erased after you upgrade to the new version of OS X. If you need to download it again, open the Mac App Store, then open the Purchase page. You’ll be able to download Mac OS X Lion Install again.

The best time to use Lion DiskMaker is when you just finish downloading OS X from the Mac App Store. Create your disk with Lion Disk Maker , then install OS X.

I got my version of OS X pre-installed with my Mac. How can I get the OS X installer ? 

There are two ways to do it.

– If you already purchased OS X on the Mac App Store (and therefore have a valid copy of OS X Install application), you can download the latest installer from Mac App Store first. This installer is compatible with Macs pre-equiped with your version of OS X.

– If you did not purchase OS X, but want to get an Install disc, there is a way to get the InstallESD.dmg file for your Mac. The method is not really easy though. Check Macworld for the full story. After you got the InstallESD.dmg file, use it to build your key or DVD with Lion DiskMaker.

I encountered the following message: The disk could not be created because of an error: An error occurred: 1. hdiutil: attach failed – No such file or directory

This happens if you chose the wrong Mac OS X Lion Install application, or if you mounted manually the InstallESD.dmg file first.

The simple answer is: don’t do this 🙂 Lion DiskMaker is clever enough to detect your copy of OS X Install itself. Then it will mount the DMG file itself.

Yes, that’s cool, but I don’t have the complete OS X Install app and I just kept the InstallESD.dmg file. So do I have to re-download Lion again?

Don’t worry, if it does not find your OS X Install app, Lion DiskMaker will allow to select manually an InstallESD.dmg file.

Can I use a FireWire or SD-Card?

Yes, you can, though the USB drive has the advantage of being « universal » and works on any Mac.

My drive was completely erased!

DiskMaker X proposes two different ways to make a bootable disk:

– You can choose to use a dedicated 8 GB thumb drive ;

– Or you can choose a volume from any drive.

If you choose the 8 GB thumb drive option, the WHOLE disk will be erased. If you choose the second option, ONLY the dedicated volume will be erased, leaving any other volume on your disk intact.

However, if you chose the wrong option, Lion DiskMaker will list every volume that may be erased at the end of the process. Read slowly 🙂

And of course, backup any file on your drive before using the software if necessary. And use a dedicated, small drive (a 8 GB USB key is incredibly cheap these days).

Why did you remove the option to use a 4 GB USB Thumb drive?

The OS X install apps tend to be bigger and bigger with each new release. I used to remove some less essential package in the previous versions of Lion DiskMaker, but this could create some issues (many people complained that the installer then failed when installing OS X).

Also, the price of 8 GB USB thumb stick drives fell , as you can get an 8 GB drive for less than $7 now. So please do yourself a favor, and get one. This drive should be « future-proof » (until Apple makes OS X installer larger than 8 GB…).

Can I redistribute this software ?

Sure, as long as you mention the author and don’t suppress any comment or change anything in its package.

Booting from the DVD is slooooow as hell…

A DVD will always be slower than a USB key, and it seems Lion’s disk image is not optimized for use with optical disks. Avoid it, and use a USB key.

Why did you not rename Lion Diskmaker now that Mountain Lion is available ?

Well, I like this name better than « OS X Diskmaker ». That’s it.

(also: « Lion Diskmaker » should make Apple’s lawyers go less ballistic than « OS X Diskmaker ».

So yes I changed my mind on the last one 🙂

This post is also available in: French

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