I have been working on this app for months now and from as far back as I can remember I have never had an issue with segues. The code is unchanged in terms of calling
I ran into the same issue and the fixes in this post (Xcode 7 crash: [NSLocalizableString length] 30000) solved the issue for me.
The first is to enable a localisation other than the base for the storyboard (see https://stackoverflow.com/a/32688815/3718974)
The second is to turn off the base localisation (see https://stackoverflow.com/a/32719247/3718974)