Undefined variable $uploadPath

Hi @lorro,
thank you for the feedback! Could you open that file again and send me the the var_dump($wp_upload_dir);? That would help a lot!

    public function __construct() {
        $this->_basepath    = realpath(WP_CONTENT_DIR);
        $this->_librarypath = str_replace($this->_basepath, '', N2LIBRARY);

        $this->paths[] = $this->_basepath;

        $wp_upload_dir = wp_upload_dir();
        var_dump($wp_upload_dir);

        $scheme        = parse_url($wp_upload_dir['basedir'], PHP_URL_SCHEME);

Hi @lorro,
I think I found the issue. Could you try to open filesystem.php and replace the __construct method with the following:

    public function __construct() {
        $this->_basepath    = realpath(WP_CONTENT_DIR);
        $this->_librarypath = str_replace($this->_basepath, '', N2LIBRARY);

        $this->paths[] = $this->_basepath;

        $wp_upload_dir = wp_upload_dir();
        $scheme        = parse_url($wp_upload_dir['basedir'], PHP_URL_SCHEME);

        /**
         * Amazon S3 storage has s3://my-bucket/uploads upload path. If we found a scheme in the path we will
         * skip the realpath check so it won't fail in the future.
         * @url https://github.com/humanmade/S3-Uploads
         */
        if (!in_array($scheme, array('s3'))) {
            $uploadPath = rtrim(realpath($wp_upload_dir['basedir']), "/\\");
            if (empty($uploadPath)) {
                echo 'Error: Your upload path is not valid or does not exist: ' . $wp_upload_dir['basedir'];
                $uploadPath = rtrim($wp_upload_dir['basedir'], "/\\");
            }
        } else {
            $uploadPath = $wp_upload_dir['basedir'];
        }

        if (strpos($this->_basepath, $uploadPath) !== 0) {
            $this->paths[] = $uploadPath;
        }

        self::measurePermission(N2Platform::getPublicDir());
    }

Does it solve the issue?

Sure. I use something like var_dump which does not show front end. I have redacted my domain name.

[18-Jul-2018 06:20:02 UTC] Array
(
    [path] => C:\Inetpub\vhosts\domain.com\httpdocs/wp-content/uploads/2018/07
    [url] => https://www.domain.com/wp-content/uploads/2018/07
    [subdir] => /2018/07
    [basedir] => C:\Inetpub\vhosts\domain.com\httpdocs/wp-content/uploads
    [baseurl] => https://www.domain.com/wp-content/uploads
    [error] => 
)

$scheme gives the string: C

Yes, the revised__construct function does not give the undefined variable message. Thank you.

I thank you for the report, @lorro. We will release this bugfix today with a new version.