Problems with _font-face.scss in Gantry (with Grav)

Hello there.

I’m trying to customize the hydrogen theme for Gantry 5 and I’ve made some changes in presets.yaml to create new presets. Suddenly, after refresh the styles section, in Gantry admin, system displays the following message:

#259 function font-source-declaration user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/css3/_font-face.scss on line 16
#260 function font-url-prefixer user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/css3/_font-face.scss on line 9
#261 mixin font-face user/plugins/gantry5/engines/nucleus/scss/nucleus/theme/mixins/_typography.scss on line 13
#262 mixin import-font user/themes/g5_hydrogen/scss/hydrogen/_typography.scss on line 2
#263 function assign-inputs user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/addons/_text-inputs.scss on line 109
#264 function assign-inputs user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/addons/_text-inputs.scss on line 108
#265 function assign-inputs user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/addons/_buttons.scss on line 56
#266 function assign-inputs user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/addons/_buttons.scss on line 55
#267 function assign-inputs user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/addons/_buttons.scss on line 54
#268 function em user/plugins/gantry5/engines/nucleus/scss/vendor/bourbon/functions/_modular-scale.scss on line 21

I have not modified anything in the SCSS files or others.

Do you know something about this issue?

Thanks in advance.