Can’t update 1.20.1x64 to 1.26.1

I tried to update from 1.20.1 to 1.26.1 on my Macbook (macOS Sierra 10.12.6). When I select ‘Restart and Install’ it shuts down and when i reopen then is same again without install update.

If you have been on 1.20.1 this whole time, there’s a chance that something went wrong with installing Squirrel or Atom in the first place. Try uninstalling Atom and reinstalling from a new executable downloaded from the web site. You won’t lose any of your personal data or settings, since they’re all kept in ~/.atom.