Hi @jecht83 Really sorry you’re having this problem…still 
Had hoped @freak4pc’s bootstrap file / approach was the silver bullet. It does work much better and I am not able to reproduce the problem you’re having, but here are some things you can try:
- Change the scheme destination to a simulator or device instead of My Mac
- Do steps 1-6 of these nuke and repave steps
- Download a new set of the project files
I have found that the latest Xcode playgrounds work fine now for new projects, but still seem to be problematic when opening projects created in older versions (
).
So, if all of the above steps do not resolve the issue for you, you could download this starter playground I created, which has RxSwift and RxCocoa added to it. This does not use the bootstrap script. Just be sure to build first every time you open it. And if you do use this starter playground throughout the book, also be sure to copy in any code and resources from the original playground for that chapter.
Good luck!