Did you fork Parse-Swift and build it in your Xcode along with running the playgrounds like I mentioned in my previous comment?
Did you try to build the sample project I posted?
Did you update your Xcode?
If so, can you tell us what happened?
ParsSwift is built for multiple versions of Xcode, some of which are not even aware of websockets and that error isn’t present. As I mentioned this seems like you configured something incorrectly or attempting to use the SDK in your project in an unknown way.