Dispatch Theme css Errors

Hi, I've just started working on a site using the "Dispatch" theme, however the theme is throwing up two css errors in the customizer.

Line 208: "Expected RBRACE at line 208, colun 42."
Line 209: "Unexpected token '1fr' at line 209, colum 29."

    .wpsp-grid .wp-show-posts {
        grid-template-columns: repeat(8, 1fr);
        grid-template-rows: 1fr auto;
    }

Not sure if these are actual css errors or a css lint issue.
Anyone any idea?

Thanks, Anthony