Hello,
Sometimes when you import demo with a great number of the images the server timeout is not enough to import all the media that demo has and this error occurred.
I’ve chosen the demo import again and at the demo content installation step don’t check all but media only – https://prnt.sc/vroyy1
Also, I’ve done some changes to your site to make it looks like the default demo. Please check the site now.
To fix this displaying – https://prnt.sc/vrp09e , download icon-box.php file from this page – https://dropmefiles.com/YZapO and re-upload it via FTP into wp-content/plugins/et-core-plugin/app/controllers/shortcodes/ folder.
Let us know if you need any further assistance.
Regards