Problem with Opencart's interface, it's very sketchy

I ve installed Opencart 2.0.0.0 and it's been perfect. i ve liked "moderns theme" but i could not install it because it only compatible with OpenCart Version: 1.5.5.1 / 1.5.6 / 1.5.6.1 / 1.5.6.2 / 1.5.6.3 / 1.5.6.4. Then i ve installed Opencart 1.5.6.4 and t had this problem



Opencart's interface was very sketchy and i counld not do anything, please help me

The values in your /config.php and possibly your /admin/config.php are incorrect. This is causing links to things like the css stylesheets to be broken, essentially destroying the layout.

please show me how to fix it, i tried to install another opencart version (1.5.6.3), but i still had a same problem (