wp_cache_get not working

Hello,

Some strange things happaning,
doing everithing like in documentation or samples in web, but wp_cache_get not working.. always returning false

so, my code:

final protected function cacheGet( $update = false ) {

		$directory	= $this->settings->getPath();
		$cacheKey	= md5( $this->settings->getModule()->getSlug( $directory ) );
		$cacheGroup	= md5( get_called_class() );

		$result 	= wp_cache_get( $cacheKey, $cacheGroup ); // === false

		if( false === $result || $update ) {

			echo '<pre>'; var_dump( 'no cache' ); echo '</pre>';

			$result = array();

			$files = new \RecursiveIteratorIterator( new \RecursiveDirectoryIterator( $directory, \FilesystemIterator::SKIP_DOTS ) );

			$files = $this->validateFiles( $files );

			foreach( $files as $file )
				if( ( $content = $this->read( $file ) ) && is_array( $content ) )
					$result[] = $content;

			wp_cache_set( $cacheKey, $result, $cacheGroup, YEAR_IN_SECONDS );

			$testCache = wp_cache_get( $cacheKey, $cacheGroup ); // === $result

		}

		return $result;

	}

if i try var_dump( wp_cache_get( $cacheKey, $cacheGroup ) ); after wp_cache_set it returns stored data so wp_cache_set works fine, but on reload the upper wp_cache_get returns false, like if cashe is not saved somewhere or not readed when aplication is loaded..

due to my aplication these function is called in plugins_loaded action or after it ( if plugin is loaded after that action ).
I don’t know, may be it should be loaded after some specific action only ?

Also tryed adding define('WP_CACHE', true); in settings.php after WP_DEBUG is defined – same result.

Thought may be $cacheKey is to long, changed on my_key and remuved $cacheGroup – not working.

I’m curently running on localhost, with openserver, php5.5, windows10…

Can someone help me ?