"Cannot load app" error when pressing the back button on Firefox

For the past few weeks when I try to use the “Back Button” to get back to Discourse after visiting any other site, I get a white background with this message:

Cannot load app

It looks like you are offline! Please check your network connection and try again.

I can use the Refresh Button and everything goes back to normal. Windows 10, FireFox 59.0.2

Firefox problem, or Discourse problem?

It is related to this topic.

It was a bug in mozilla firefox and should be fixed in the next firefox update