This happens also on a blank Master/Detail project when using XCode 6.2 beta.
In other words: it works on the simulator but gives me the error below when I run it on an iPhone 5 with iOS 7.1 installed (I don't have any other device to test it on).
Below is what I get adding the exception breakpoint.
I found the following previous Q/A but it does not seem to happen in the same case as mine. Why would it work on the simulator?
Is this an XCode 6.2 bug? Can anyone reproduce it?