The Problem

While publishing your .ipa file to the App Store, you may encounter the following:

Return status of iTunes Transporter was 1: ERROR ITMS-90685: "CFBundleIdentifier Collision. There is more than one bundle with the CFBundleIdentifier value XXX under the iOS application

Not the most helpful message. You will likely see the above if your app has code seperated into a framework.

The Solution

The problem is that you have likely embedded the same framework twice, or have two separate frameworks with the same identifier. You should see something similar to this:

One solution would be to change it to this:

Instead, embedding the library instead into the main application.

This may be related to ITMS-90205/ITMS-90206.