As of November 28th, 2017, Google has deprecated their Realtime API. Existing realtime applications (such as those you may have set up according to these instructions) will still work until December 2018, but new applications will not be able to use the Realtime API. See the discussions here and here for more information. NOTE: this is beta software and is rapidly changing. Files stored on Google Drive using this plugin should still be backed-up elsewhere.