Text/fonts screwed up in FF

Firefox Development
6

There seems to be a problem with Open Sans and perhaps a couple other web fonts in 78.12.0esr on MacOS. Here is the open bug:

I’m not aware of a workaround at the moment. There are methods to override specific fonts using an extension like Stylus or rules in a userContent.css file. As an example:

/*** Replace Open Sans with Arial ***/
@font-face {
  font-family: 'Open Sans';
  src: local('Arial');
}

/* Heavier weights */
@font-face {
  font-family: 'Open Sans'; font-style:normal; font-weight:600;
  src: local('Arial Bold');
}
@font-face {
  font-family: 'Open Sans'; font-style:normal; font-weight:700;
  src: local('Arial Bold');
}
@font-face {
  font-family: 'Open Sans'; font-style:normal; font-weight:800;
  src: local('Arial Bold');
}

/* Italic style */
@font-face {
  font-family: 'Open Sans'; font-style:italic;
  src: local('Arial Italic');
}
@font-face {
  font-family: 'Open Sans'; font-style:italic; font-weight:600;
  src: local('Arial Bold Italic');
}
@font-face {
  font-family: 'Open Sans'; font-style:italic; font-weight:700;
  src: local('Arial Bold Italic');
}
@font-face {
  font-family: 'Open Sans'; font-style:italic; font-weight:800;
  src: local('Arial Bold Italic');
}

You could consider doing that as a temporary measure (of course, replace Arial with anything you prefer).