Fatal error: Maximum execution time of 30 seconds exceeded

[gladysg]

Please help me fix this.

Fatal error: Maximum execution time of 30 seconds exceeded in /home/jgonza5/public_html/wp-content/plugins/unyson/framework/helpers/class-fw-cache.php on line 189 There has been a critical error on this website.

public static function free_memory($dummy = null)
{
    **while (self::memory_exceeded() && !empty(self::$cache)) {**
        reset(self::$cache);

        $key = key(self::$cache);

        unset(self::$cache[$key]);
    }