Error trying to build after @importing new fonts

I’m trying to use custom fonts in my app, só i’ve downloaded a font (Humanist) and a icon font with some icons from Flaticon.
I’ve saved them in www/assets/fonts and app/assets/fonts, i’m currently importng the app/assets one in my app.scss file and it works fine when i run ionic serve, but when i try to build it this error is thrown:

Anyone know what’s wrong?

still needing help :frowning2:
i’ve tried importing the .css file, the .scss file and leaving just the font name