Please help me Pleaseeeee 3 days I try to fix this problem, I cant Install quickstar SJ G2Shop

the problem report

Consider using 'dppx' units, as in CSS 'dpi' means dots-per-CSS-inch, not dots-per-physical-inch, so does not correspond to the actual 'dpi' of a screen. In media query expression: only screen and (-webkit-min-device-pixel-ratio: 2), only screen and (min-resolution: 144dpi)
core.js:1

Uncaught TypeError: undefined is not a function
localhost/sb/installation/index.php#
Failed to load resource: net::ERR_CACHE_MISS

Go to the file: /installation/index.php and find:
define('_JEXEC', 1);
=> Edit to:
define('_JEXEC', 1);
ini_set ('display_errors', 'Off');