MacOS – MacBook Air Sierra install fail: Couldn’t mount base system dmg! (error code 60)

crasherrorinstallmacos

I have a MacBook Air and I tried running a Sierra install USB on it. Everything went smoothly but it showed "An error occurred while preparing the installation."

So I looked that up on the internet and tried the following suggestions:

  • setting the date and time
  • turning the Wi-Fi on
  • resetting the NVRAM.

Regardless I kept getting the same error. I tried opening the log and showing all logs. See log below:

Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Hardware: MacBookAir3,1 @ 1.40 GHz (x 2), 2048 MB RAM
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Running OS Build: Mac OS X 10.12.6 (16G29)
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: DYLD_NO_FIX_PREBINDING=1
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: PATH=/usr/bin:/bin:/usr/sbin:/sbin
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: PWD=/
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: XPC_FLAGS=0x0
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: XPC_SERVICE_NAME=0
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: SHLVL=1
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: __OSINSTALL_ENVIRONMENT=1
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: CI_DEFAULT_OPENCL_USAGE=0
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: OS_INSTALL=1
Aug 17 21:41:51 MacBook-Air InstallAssistant[590]: Env: _=/System/Library/CoreServices/Language Chooser.app/Contents/MacOS/Language Chooser
Aug 17 21:41:52 MacBook-Air osinstallersetupd[591]: OSISChunkedDownload loaded...
Aug 17 21:41:52 MacBook-Air osinstallersetupd[591]: OSISAppStoreDownload loaded...
Aug 17 21:41:52 MacBook-Air osinstallersetupd[591]: Checking Software Update catalog URL https://swscan.apple.com/content/catalogs/others/index-10.12customerseed-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz
Aug 17 21:41:52 MacBook-Air osinstallersetupd[591]: mountDiskImageWithPath: /Volumes/Image Volume/Install macOS Sierra.app/Contents/SharedSupport/InstallESD.dmg
Aug 17 21:41:54 MacBook-Air osinstallersetupd[591]: Mounting disk image complete, results dict = {
        "system-entities" =     (
                    {
                "content-hint" = "GUID_partition_scheme";
                "dev-entry" = "/dev/disk20";
                "potentially-mountable" = 0;
                "unmapped-content-hint" = "GUID_partition_scheme";
            },
                    {
                "content-hint" = EFI;
                "dev-entry" = "/dev/disk20s1";
                "potentially-mountable" = 1;
                "unmapped-content-hint" = "C12A7328-F81F-11D2-BA4B-00A0C93EC93B";
                "volume-kind" = msdos;
            },
                    {
                "content-hint" = "Apple_HFS";
                "dev-entry" = "/dev/disk20s2";
                "mount-point" = "/Volumes/OS X Install ESD";
                "potentially-mountable" = 1;
                "unmapped-content-hint" = "48465300-0000-11AA-AA11-00306543ECAC";
                "volume-kind" = hfs;
            }
        );
    }
Aug 17 21:41:54 MacBook-Air osinstallersetupd[591]: Mount point /Volumes/OS X Install ESD
Aug 17 21:41:54 MacBook-Air osinstallersetupd[591]: osinstallersetupd registered client
Aug 17 21:41:55 MacBook-Air Unknown[508]: Aug 17 21:41:55  InstallAssistant[590] <Error>: CGColorSpaceCreateWithName failed for kCGColorSpaceITUR_709
Aug 17 21:41:55 MacBook-Air Unknown[508]: Aug 17 21:41:55  InstallAssistant[590] <Error>: CGColorSpaceCreateWithName failed for kCGColorSpaceITUR_2020
Aug 17 21:41:55 MacBook-Air Unknown[508]: Aug 17 21:41:55  InstallAssistant[590] <Error>: CGColorSpaceCreateWithName failed for kCGColorSpaceROMMRGB
Aug 17 21:41:55 MacBook-Air Unknown[508]: 2019-08-17 21:41:55.641 InstallAssistant[590:25524] NSColorList could not parse color list file /System/Library/Colors/System.clr
Aug 17 21:41:55 MacBook-Air Unknown[508]: 2019-08-17 21:41:55.676 InstallAssistant[590:25524] Failed to connect (continuePane) outlet from (IASetupWindowController) to (NSTextField): missing setter or instance variable
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air InstallAssistant[590]: DM ..F-[DMManager(PrivateMethods) clientConforms:error:]: currentThread=32023=0x7d17 expectedThread=775=0x307
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/BaseSystemResources.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.BaseSystemResources";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/Essentials.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.Essentials";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/OSInstall.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.OSInstall";
        options = 16;
        version = "10.12.6.1";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/FirmwareUpdate.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.FirmwareUpdate";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/EmbeddedOSFirmware.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.EmbeddedOSFirmware";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: version = 10.12.6
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: OSISCustomizationController: Using version 10.12 from InstallSystemSizes.plist
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: OSISCustomizationController: System size: 10515609460 bytes
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/BaseSystemResources.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.BaseSystemResources";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/Essentials.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.Essentials";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/OSInstall.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.OSInstall";
        options = 16;
        version = "10.12.6.1";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/FirmwareUpdate.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.FirmwareUpdate";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:55 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/EmbeddedOSFirmware.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.EmbeddedOSFirmware";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:41:58 MacBook-Air osinstallersetupd[591]: mountDiskImageWithPath: /Volumes/Image Volume/Install macOS Sierra.app/Contents/SharedSupport/InstallESD.dmg
Aug 17 21:42:00 MacBook-Air osinstallersetupd[591]: Mounting disk image complete, results dict = {
        "system-entities" =     (
                    {
                "content-hint" = "GUID_partition_scheme";
                "dev-entry" = "/dev/disk20";
                "potentially-mountable" = 0;
                "unmapped-content-hint" = "GUID_partition_scheme";
            },
                    {
                "content-hint" = EFI;
                "dev-entry" = "/dev/disk20s1";
                "potentially-mountable" = 1;
                "unmapped-content-hint" = "C12A7328-F81F-11D2-BA4B-00A0C93EC93B";
                "volume-kind" = msdos;
            },
                    {
                "content-hint" = "Apple_HFS";
                "dev-entry" = "/dev/disk20s2";
                "mount-point" = "/Volumes/OS X Install ESD";
                "potentially-mountable" = 1;
                "unmapped-content-hint" = "48465300-0000-11AA-AA11-00306543ECAC";
                "volume-kind" = hfs;
            }
        );
    }
Aug 17 21:42:00 MacBook-Air osinstallersetupd[591]: Mount point /Volumes/OS X Install ESD
Aug 17 21:42:00 MacBook-Air osinstallersetupd[591]: Got and processed license agreement message
Aug 17 21:42:15 MacBook-Air InstallAssistant[590]: Failed to check if a disk is FDE.
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Helper tool loaded
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/BaseSystemResources.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.BaseSystemResources";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/Essentials.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.Essentials";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/OSInstall.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.OSInstall";
        options = 16;
        version = "10.12.6.1";
    }) missing reference.
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/FirmwareUpdate.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.FirmwareUpdate";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Specifier (<PKPackageSpecifier>:
    {
        URL = "file:///Volumes/OS%20X%20Install%20ESD/Packages/EmbeddedOSFirmware.pkg";
        authLevel = 2;
        displayName = macOS;
        identifier = "com.apple.pkg.EmbeddedOSFirmware";
        options = 16;
        version = "10.12.6.1.1.1500089887";
    }) missing reference.
Aug 17 21:42:22 MacBook-Air osinstallersetupd[591]: Using product <OSISSharedSupportProduct: 0x7fca96dadd80> at distance 10
Aug 17 21:42:24 MacBook-Air osinstallersetupd[591]: Using product <OSISInstallMediaProduct> based on media at /Volumes/OS X Install ESD at distance 5
Aug 17 21:42:24 MacBook-Air osinstallersetupd[591]: No available package ref for compatibility update. Ignoring.
Aug 17 21:42:24 MacBook-Air osinstallersetupd[591]: OSISDownloadOperation: totalEstimate=382.000000, significantDownload=1
Aug 17 21:42:24 MacBook-Air osinstallersetupd[591]: Operation queue started
Aug 17 21:42:26 MacBook-Air osishelperd[597]: Privilaged helper tool loaded.
Aug 17 21:42:26 MacBook-Air osishelperd[597]: Will not add removal tool because target is not /.
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: Using product PKSecureNetEnabledProduct <file:///Volumes/Macintosh%20SSD/macOS%20Install%20Data/> at distance 5
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: Using product <OSISSoftwareUpdateCatalogProduct: 0x7fca96fb3e30> at distance 25
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: OSISDownloadOperation: totalEstimate=382.000000, significantDownload=1
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: Retrieving 3 packages (5.015 GB)
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: Retrieved package com.apple.pkg.CompatibilityUpdate (http://swcdn.apple.com/content/downloads/17/04/031-83163/n8thccuwnoqetn1kyn53bheb4nb7pw3wbv/OSX_10_12_IncompatibleAppList.pkg)
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: No native mechanism to verify InstallInfo.plist
Aug 17 21:42:27 MacBook-Air osinstallersetupd[591]: Retrieved package com.apple.installer.info (file:///Volumes/Image%20Volume/Install%20macOS%20Sierra.app/Contents/SharedSupport/InstallInfo.plist)
Aug 17 21:52:20 MacBook-Air powerd[152]: Assertion TimedOut. Type:UserIsActive Name:'com.apple.iohideventsystem.queue.tickle.4294967965.11' Id:0x900008011 Process:hidd [System: PrevIdle DeclUser kDisp]
Aug 17 21:52:44 MacBook-Air powerd[152]: Display is turned off
Aug 17 21:52:44 MacBook-Air powerd[152]: Assertion Summary. Type:NoIdleSleepAssertion Name:'OSInstaller Setup' Id:0x10000801e Process:osinstallersetupd [System: PrevIdle]
Aug 17 21:52:44 MacBook-Air powerd[152]: Assertion Summary. Type:ExternalMedia Name:'com.apple.powermanagement.externalmediamounted' Id:0x800008000 Process:powerd [System: PrevIdle]
Aug 17 21:53:00 MacBook-Air powerd[152]: Display is turned on
Aug 17 21:53:00 MacBook-Air powerd[152]: Assertion Created. Type:UserIsActive Name:'com.apple.iohideventsystem.queue.tickle.4294967965.11' Id:0x900008020 Process:hidd [System: PrevIdle DeclUser kDisp]
Aug 17 22:08:12 MacBook-Air osinstallersetupd[591]: No native mechanism to verify InstallESD.dmg
Aug 17 22:08:12 MacBook-Air osinstallersetupd[591]: Retrieved package com.apple.dmg.InstallESD (file:///Volumes/Image%20Volume/Install%20macOS%20Sierra.app/Contents/SharedSupport/InstallESD.dmg)
Aug 17 22:08:14 MacBook-Air osinstallersetupd[591]: Verifying InstallOS.pkg/InstallESD.dmg
Aug 17 22:09:30 MacBook-Air osinstallersetupd[591]: Skipping preflighting firmware since we're booted into the Recovery OS
Aug 17 22:09:30 MacBook-Air osinstallersetupd[591]: Operation queue succeeded
Aug 17 22:09:30 MacBook-Air powerd[152]: Assertion Released. Type:NoIdleSleepAssertion Name:'OSInstaller Setup' Id:0x10000801e Process:osinstallersetupd [System: DeclUser kDisp]
Aug 17 22:09:30 MacBook-Air InstallAssistant[590]: Finished operation queue
Aug 17 22:09:34 MacBook-Air osishelperd[597]: Wrote prev-lang:kbd=en:15
Aug 17 22:09:34 MacBook-Air osishelperd[597]: Current phase is: Language Chooser
Aug 17 22:09:40 MacBook-Air osishelperd[597]: mountDiskImageWithPath: /Volumes/Macintosh SSD/macOS Install Data/InstallESD.dmg
Aug 17 22:10:13 MacBook-Air osishelperd[597]: Couldn't mount base system dmg! (error code 60)
Aug 17 22:10:13 MacBook-Air osishelperd[597]: IATOOL: Failed to mount outer dmg
Aug 17 22:10:13 MacBook-Air osinstallersetupd[591]: Unable to setup bless on disk.
Aug 17 22:13:04 MacBook-Air Unknown[508]: 2019-08-17 22:13 InstallAssistant[590] (FSEvents.framework) FSEventStreamStart: ERROR: FSEvents_connect() => Unknown service name (1102)

Can anyone shed some light on this? How do I proceed?

Best Answer

In my opinion the error message is misleading. Probably it's the same broken certification chain (as in this question & answer: El Capitan bootable installer on Mac Mini - “A required download is missing”) resulting in a slightly different message.

So download Sierra, open the dmg and the included pkg and install the Sierra installer.app to /Applications.

From there create a new installer thumb drive with:

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ Sierra.app

Replace MyVolume with the name of your freshly erased thumb drive volume (probably "Untitled").

Boot to the thumb drive and install Sierra.