Check your _custom-variables.scss in your theme\sass\custom around line 69:
// Font Family Import $font-family-import: false; @import url($font-family-import);
I had those too. I took the previous version of the theme and it was OK. I think this was fixed recently so updating your theme would do the trick.
It looks like this in the file
// Font Family Import / Google Fonts - Roboto $font-family-import: 'https://fonts.googleapis.com/css?family=Roboto'; @import url($font-family-import);