Today I learned not to use the copy of Ruby labeled preview. It is only for testing and could be bug filled. So I installed Ruby 2.3. (I think it actually installed 2.3.7?) Max (SK) said it was a stable Ruby and I set it as my default. Fortunately, I’m not so far along that this is a huge problem. And, I’m working my way through the course again after the Barometer fiasco.
rvm install 2.3
rvm –default use 2.3