dosamigos\fileupload\actions\AbstractUploadAction::init PHP Method

    public function init()
    {
        if (!isset($this->className, $this->ownerLinkTableOwnerAttribute, $this->ownerLinkTable, $this->ownerLinkTableAttribute)) {
            throw new InvalidConfigException('"className", "ownerLinkTableOwnerAttribute", "ownerLinkAttribute" and "ownerLinkTable" cannot be null');
        }
        parent::init();
    }