Windows Phone (or Zune HD) and OS X El Capitan

In Mac OS X 10.11 "El Capitan", Microsoft's Windows Phone app does no longer work. Here's how you can fix the problem by updating the "libusb" library the app uses. Of course, I cannot guarantee that these instructions will work for you. You're doing this at your own risk.
I am not associated with Microsoft in any way, and they have not endorsed this solution (or provided any help).

Check if you have version 3.1.1 of the Windows Phone app. Unfortunately, Microsoft has removed the Windows Phone app from the Mac App Store, so you cannot download the app if you don't have it already. I cannot help you in this case. If you had previously downloaded the app, you might still be able to find it on the "Purchased" tab in the App Store.
Launch the Windows Phone app and close it again.
Create a backup copy of the Windows Phone app. If something goes wrong, you can restore the backup and try it again.
These instructions will only fix the 64-bit version of the app. Should you have activated the "Open in 32-bit mode" checkbox in the Get Info dialog, uncheck it again.
Download this file, unpack the zip file, select the two dylib files (libusb.dylib and libusb-standard.dylib) and press Cmd-C to copy them. (You can find the LGPL-licensed source code here.)
Ctrl-click the Windows Phone app and choose "Show Package Contents". Open the "Contents" folder and then the "Frameworks" folder.
Now paste the two dylib files by pressing Cmd-V. Confirm that you want to replace the existing file. The Finder will probably need your administrator password.
That's it. You will now be able to sync your WP 8 phone with El Capitan. If you still have a WP 7 phone, you need to follow these instructions as well if you haven't done so already.
If you already use macOS Sierra, please go here now.
By the way, if you don't see your iTunes music in the Windows Phone app, enable the iTunes Library XML file.
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