You'll likely need to clear the cache under Optimization in the Settings menu.

Have tried this but it's still calling to the cache folder

Assuming you're using Fruitful?

I had some memory issues with the LESS files. I got around it by turning off caching (during development), made the edits in the LESS file, cleared cache, refreshed page. Turn on caching when finished.

LESS is still a bit out of my grasp in practice so it's still a bit of voodoo to me. I think, and I welcome any corrections here, that the LESS file is processed into the cache and so that's where the theme/C5 will read it from.

Thanks for this have tried this but still not updating the CSS - any other ideas??

I've come across many threads which mention exactly the same problem, so I came up with a solution for everyone. Please bear in mind this solution is for the latest version of Concrete5 (v5.7.5.9)

Step 1:

Copy the /concrete/src/Page/Theme/Theme.php to /application/src/Page/Theme (create the /src directory within the /application directory)

Step 2:

Open /application/src/Page/Theme/Theme.php and replace everything with the following:

namespace Application\Src\Page\Theme;

use Config;
use Environment;

class Theme extends \Concrete\Core\Page\Theme\Theme
{
public function getStylesheetObject($stylesheet)
{
$env = Environment::get();
$output = $this->getStylesheetCachePath().'/'.DIRNAME_CSS.'/'.$this->getThemeHandle();
$relative = $this->getStylesheetCacheRelativePath().'/'.DIRNAME_CSS.'/'.$this->getThemeHandle();
$r = $env->getRecord(
DIRNAME_THEMES.'/'.$this->getThemeHandle().'/'.DIRNAME_CSS.'/'.$stylesheet,
$this->getPackageHandle()
);

$stylesheet = new \Application\Src\StyleCustomizer\Stylesheet($stylesheet, $r->file, $r->url, $output, $relative);

return $stylesheet;
}

public function getStylesheet($stylesheet)
{
$stylesheet = $this->getStylesheetObject($stylesheet);
$styleValues = $this->getThemeCustomStyleObjectValues();
if (!is_null($styleValues)) {
$stylesheet->setValueList($styleValues);
}
if (!$this->isThemePreviewRequest()) {
if (!$stylesheet->outputFileExists() || !Config::get('concrete.cache.theme_css')) {
$stylesheet->output();
} else {
$outputPathLess = str_replace( '.css', '.less', $stylesheet->getOutputPath() );
if (filesize($stylesheet->getSourcePath()) != filesize($outputPathLess) ) {
$stylesheet->output();
}
}
}
$path = $stylesheet->getOutputRelativePath();
if ($this->isThemePreviewRequest()) {
$path .= '?ts='.time();
}

return $path;
}
}

AND... replace \Concrete\Core\Page\Theme\Theme with \Application\Src\Page\Theme\Theme, so the theme classes extends from our version of the core theme class.

Step 3:

Copy across the /concrete/src/StyleCustomizer/Stylesheet.php to /application/src/StyleCustomizer

Step 4:

Modify the Stylesheet class file output function with the following:

public function output()
{
$css = $this->getCss();
$sourceLess = file_get_contents($this->file);
$outputPathLess = $this->outputDirectory . '/' . $this->stylesheet;
$path = dirname($this->getOutputPath());
if (!file_exists($path)) {
@mkdir($path, Config::get('concrete.filesystem.permissions.directory'), true);
}
file_put_contents($this->getOutputPath(), $css);
file_put_contents($outputPathLess, $sourceLess);
}

AND... append the following function anywhere within the Stylesheet class

public function getSourcePath()
{
return $this->file;
}

Step 5:

Enjoy!