Shopify Website Error

Hi, I am doing this for a favour for someone so only have $8 please do not apply if you can not do for this. I know it is a very quick fix. When my friend was messing with the fonts on their shopify theme the theme broke. Attached is the screenshot of the error code it needs fixing in next hour ideally please. I do have the original theme files if that helps but need to lose nothing that has already been changed to the site If you can do it then I have a lot of work in the future Many thank Nick