Strict Standards Error after activating the plugin

Hi, I got this error after activating the plugin.

Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method WC_Admin_Assets::admin_styles() should not be called statically in C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php on line 298

Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method WC_Admin_Assets::admin_scripts() should not be called statically in C:\xampp\htdocs\wordpress\wp-includes\class-wp-hook.php on line 298

I’m using this in my localhost. The plugin’s activate but what causes this error? I have WP_DEBUG set to true.

Please help. Thank you.