macOS iBooks Code Results show as <ERROR>

[nteissler]

Platform: macOS .epub (Macbook Pro Retina 15") Version: 1.0 (2017-06-02) Issue: The results of code that is supposed to be run shows as <ERROR> throughout the book Description: Code that runs and is supposed to print a result instead shows <ERROR>. In the playground versions, the code runs and quicklook shows the proper results.

Sample

See sections 2.5, 3.5, 4.3, 4.5, etc. (search for <ERROR>)