Bloom.Book.BookStorage.GetValidateErrors C# (CSharp) Method

        public string GetValidateErrors()
        {
            if (!string.IsNullOrEmpty(ErrorMessagesHtml))
                return "";
            if (!Directory.Exists(_folderPath))
            {
                return "The directory (" + _folderPath + ") could not be found.";
            }
            if (!RobustFile.Exists(PathToExistingHtml))
            {
                return "Could not find an html file to use.";
            }

            return ValidateBook(_dom, PathToExistingHtml);
        }