En includes/defines.php

define('JPATH_ROOT', implode(DIRECTORY_SEPARATOR, $parts));

define('JPATH_SITE', JPATH_ROOT);

define('JPATH_CONFIGURATION', JPATH_ROOT);

define('JPATH_ADMINISTRATOR', JPATH_ROOT . DIRECTORY_SEPARATOR . 'administrator');

define('JPATH_LIBRARIES', JPATH_ROOT . DIRECTORY_SEPARATOR . 'libraries');

define('JPATH_PLUGINS', JPATH_ROOT . DIRECTORY_SEPARATOR . 'plugins');

define('JPATH_INSTALLATION', JPATH_ROOT . DIRECTORY_SEPARATOR . 'installation');

define('JPATH_THEMES', JPATH_BASE . DIRECTORY_SEPARATOR . 'templates');

define('JPATH_CACHE', JPATH_BASE . DIRECTORY_SEPARATOR . 'cache');

define('JPATH_MANIFESTS', JPATH_ADMINISTRATOR . DIRECTORY_SEPARATOR . 'manifests');

Hay que cambiar tambien en el directorio administrator/includes/defines.php define('JPATH_SITE', JPATH_ROOT);

define('JPATH_CONFIGURATION', JPATH_ROOT);

define('JPATH_ADMINISTRATOR', JPATH_ROOT . '/administrator');

define('JPATH_LIBRARIES', JPATH_ROOT . '/libraries');

define('JPATH_PLUGINS', JPATH_ROOT . '/plugins' );

define('JPATH_INSTALLATION', JPATH_ROOT . '/installation');

define('JPATH_THEMES', JPATH_BASE . '/templates');

define('JPATH_CACHE', JPATH_BASE . DIRECTORY_SEPARATOR . 'cache');

define('JPATH_MANIFESTS', JPATH_ADMINISTRATOR . '/manifests');

En el administrator/com_cache/models/cache.php

Por la linea 115

'cachebase'		=> ($this->getState('clientId') == 1) ? JPATH_ADMINISTRATOR . '/cache' : $conf->get('cache_path', JPATH_SITE . '/cache')

Cambiar por

'cachebase'		=> ($this->getState('clientId') == 1) ? JPATH_ADMINISTRATOR . '/cache' : $conf->get('cache_path',JPATH_CACHE)