When I open Educon 2 style settings, the preview page shows this:

Undefined variable $custom_color_1: templates/educon_ii/scss/theme.scss on line 8, at column 5 Call Stack: #0 import templates/educon_ii/scss/theme.scss templates/educon_ii/scss/master.scss on line 8 #1 import templates/educon_ii/scss/master.scss (unknown file) on line 1

On the front-end, nothing but a call stack is showing:

Call stack

Function Location

1 () JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:6114 2 ScssPhp\ScssPhp\Compiler->error() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:5328 3 ScssPhp\ScssPhp\Compiler->get() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:3604 4 ScssPhp\ScssPhp\Compiler->reduce() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:3642 5 ScssPhp\ScssPhp\Compiler->reduce() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:3635 6 ScssPhp\ScssPhp\Compiler->reduce() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2954 7 ScssPhp\ScssPhp\Compiler->compileChild() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2388 8 ScssPhp\ScssPhp\Compiler->compileChildrenNoReturn() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:1931 9 ScssPhp\ScssPhp\Compiler->compileBlock() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2941 10 ScssPhp\ScssPhp\Compiler->compileChild() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2388 11 ScssPhp\ScssPhp\Compiler->compileChildrenNoReturn() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:5759 12 ScssPhp\ScssPhp\Compiler->importFile() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2713 13 ScssPhp\ScssPhp\Compiler->compileImport() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2925 14 ScssPhp\ScssPhp\Compiler->compileChild() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2388 15 ScssPhp\ScssPhp\Compiler->compileChildrenNoReturn() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:5759 16 ScssPhp\ScssPhp\Compiler->importFile() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2713 17 ScssPhp\ScssPhp\Compiler->compileImport() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2925 18 ScssPhp\ScssPhp\Compiler->compileChild() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:2388 19 ScssPhp\ScssPhp\Compiler->compileChildrenNoReturn() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:744 20 ScssPhp\ScssPhp\Compiler->compileRoot() JROOT/plugins/system/helixultimate/vendor/scssphp/scssphp/src/Compiler.php:522 21 ScssPhp\ScssPhp\Compiler->compileString() JROOT/plugins/system/helixultimate/src/Core/HelixUltimate.php:1105 22 HelixUltimate\Framework\Core\HelixUltimate->add_scss() JROOT/templates/educon_ii/index.php:120 23 require() JROOT/libraries/src/Document/HtmlDocument.php:721 24 Joomla\CMS\Document\HtmlDocument->_loadTemplate() JROOT/libraries/src/Document/HtmlDocument.php:776 25 Joomla\CMS\Document\HtmlDocument->_fetchTemplate() JROOT/libraries/src/Document/HtmlDocument.php:612 26 Joomla\CMS\Document\HtmlDocument->parse() JROOT/libraries/src/Application/CMSApplication.php:1012 27 Joomla\CMS\Application\CMSApplication->render() JROOT/libraries/src/Application/SiteApplication.php:724 28 Joomla\CMS\Application\SiteApplication->render() JROOT/libraries/src/Application/CMSApplication.php:298 29 Joomla\CMS\Application\CMSApplication->execute() JROOT/includes/app.php:61 30 require_once() JROOT/index.php:32