The reason is that it remove the polyfilled `window` in ExecJS environment[1]. And it turns out our code base reference `window` in various places. So while I am fixing on this, by locking the version of react-rails to `1.9.0` will make it work as before. [1] https://github.com/reactjs/react-rails/pull/615
The reason is that it remove the polyfilled
windowin ExecJS environment[1]. And it turns out our code base referencewindowin various places.So while I am fixing on this, by locking the version of react-rails to
1.9.0will make it work as before.[1] reactjs/react-rails#615