Band-in-a-Box 2018 and earlier for Mac - Fix for "wrong architecture" crash at bootup.

Some users with Mac OS 10.14 (Mojave) and earlier have suddenly found that they cannot launch Band-in-a-Box at all on their computers after an Apple software update. This only occurs with 32-bit versions of Band-in-a-Box for Mac (Versions 2018 and earlier) and does not apply to version 2019 or higher because they are 64-bit.

Please read below carefully to determine if these instructions apply to you, since this is only relevant for a very specific problem.

Last updated:  Monday, 20 April 2020

Determine if these instructions apply to you.

  1. You have Band-in-a-Box 2018 or earlier.
  2. You have macOS 10.14 (Mojave) or earlier.
  3. Band-in-a-Box does not launch at all on your system, and instead crashes immediately. When you view the crash report, it mentions "wrong architecture" early in the report, and references MobileDevice. For example you will see the following text:
    /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

Additionally, you can confirm you have the problem by inspecting the MobileDevice file:

  1. Open Terminal (/Applications/Utilities/
  2. Type or paste in the following command at the prompt:
    file /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

If the output of that command includes the text "2 architectures" and "i386", then you do NOT have this problem and should not follow this tutorial. e.g.

Mach-O universal binary with 2 architectures: [i386:Mach-O dynamically linked shared library i386] [x86_64]    <------ GOOD

If instead it only mentions "x86_64", this means it only supports 64bit apps:

Mach-O 64-bit executable x86_64  <------ BAD if this is all it says

Two possible solutions

The problem is caused by having a version of a certain MacOS system file (MobileDevice.framework) that is incompatible with 32-bit audio apps like Band-in-a-Box 2018 or earlier. This was likely installed by a recent Apple software update. There are two ways to solve this:

  • Re-install a previous version of MobileDevice.framework using the steps outlined below.
  • Upgrade your copy of Band-in-a-Box to 2020 (2019 and higher are 64-bit, so do not have this problem). If you aren't interested in any of the new content that is available (RealTracks, Styles, etc.), then the "Pro upgrade" will suffice - i.e. all of your existing RealTracks and Styles are compatible with the new application.

Installing MobileDevice.framework

If you prefer to stay at your current Band-in-a-Box version, then you need to delete the current MobileDevice.framework and install a previous version of it.

Part A - Delete the current MobileDevice.framework

You need to delete this file, otherwise the installer will not overwrite it since it is newer than the one you need to install. This isn't possible if System Integrity Protection (SIP) is enabled, so you need to disable SIP:

  1. Restart the computer in Recovery Mode (hold command+R immediately after boot sound, release when you see Apple symbol).
  2. Type in password when prompted (it should be clear that you are in Recovery Mode after this.
  3. Go to Utilities > Terminal and type:
    csrutil disable
  4. Go to Apple menu and restart (boot normally, i.e. don't go into Recovery Mode)
  5. Back up and delete MobileDevice.framework. Navigate in Finder to locate this file:
  6. Prior to deleting, you should make a copy of it, e.g. MobileDevice.framework.backup

Part B - Acquire and install MobileDevice.pkg

This is an installer package that Apple includes with some software. It can be obtained from the latest Xcode download for your OS. Since you can only download the Xcode for the latest Mac OS from the regular app store, you must create an Apple developer account to download the correct Xcode for your OS.

  1. Go to, sign in using your apple ID, and accept the agreements.
  2. Go to "Download Tools" and click on "more", or otherwise locate the "More Downloads" page.
  3. Download and install Xcode. Note: it is several gigabytes. You should install the correct version for your OS. We suggest installing Xcode 10 if you have Mojave, Xcode 9 if you have High Sierra, Xcode 8 if you have Sierra, etc.
  4. After you have downloaded and installed, find Xcode in the Applications folder. Right-click on the and click "Show Package Contents"
  5. Open Contents > Resources > Packages
  6. Double-click on MobileDevice.pkg to install, and this file should be created:
    Note: If the installer stops with "This package is incompatible with this version of macOS and may fail to install" you can get around that by (temporarily) setting your system Date/Time to October 1, 2019, and then running the install again.

Part C - Re-enable SIP.

Repeat Part A, but type this into terminal instead:

csrutil enable
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