I bought and downloaded this template in Sep 2019. I only installed today on Ubuntu 18.04/PHP7.2/MySQL5.7. Installation is ok.
But following issues are due to code:
1.) Case sensitive. This code might be developed on Windows, so the case is not sensive.
In File: templates/sj_thecool/error.php, line 44.
require_once(JPATH_LIBRARIES.'/src/document/renderer/html/HeadRenderer.php');
The path are in all small letter. But the Joomla site it is Document/Renderer/Html/HeadRenderer.php.
I fixed this, but then error in graphic mode shows:
Call to undefined function imagecreatefromjpeg()
I guess it is another case issue.
2.) jm-smartaddons/sj_thecool_template_j3x_v3.9.6/Document.html#install_with_quickstart_package
The document link is not showing. It shows source always. Not readable.
Please help fix both.