All Igor 6.x users are must upgrade to at least
Igor 6.37. There is a known issue with MacOS High Sierra and Igor notebooks for Igor versions < 7.07.
For Igor 6.37 and High Sierra users, one must kill all notebooks, which include the readme files, before saving an experiment.
All code as of June, 8 2018 has been tested on Igor 7.07 and Igor 8.0 and is compatible.
All Igor 7.x users are strongly encouraged to upgrade to at least
Igor 7.07