This error arises when another process is running when you launch the first compilation with the preparation of the code.
3.1.1. Launch the Procedure
To proceed with the automatic configuration procedure,
• Select any target, as Build or Make.
• Check no other process is running on Xcode, like indexing.
• Click on Run to launch it.
GitHub has the history of all the versions. However, the download section only has the latest release.