When uploading in Application Loader when using macOS Sierra, you might get the following error:
This happens when you use an older version of the Application Loader utility on macOS Sierra.
To fix this, you need to do the following:
- Install Xcode 8 from the Mac App Store
- Open Xcode, accept the license agreement if needed and install the required components
- Start Application Loader from the Xcode menu > Open Developer Tool > Application Loader
- Upload the IPA to iTunes Connect