ios – Why when creating NSAttributedString from html typically app throws exception “The file couldn’t be opened as a result of it isn’t within the appropriate format.”

I’ve these extensions to parse string with html tags to NSAttributedString

extension StringProtocol {
    var html2AttributedString: NSAttributedString? {
        Knowledge(utf8).html2AttributedString
    }
}

extension Knowledge {
        var html2AttributedString: NSAttributedString? {
        do {
            return strive NSAttributedString(
                information: self,
                choices: [
                    .documentType: NSAttributedString.DocumentType.html,
                    .characterEncoding: String.Encoding.utf8.rawValue
                ],
                documentAttributes: nil)
        } catch {
            bfprint("html2AttributedString: Html string parsing error: (error)",
                    tag: LogUtils.Tags.criticalDevError,
                    degree: .error)
            return  nil
        }
    }
}

The app will get unique html strings from Localizable recordsdata. Generally when the app parses the html strings with <u> tag like this “That is <u>underlined half</u>” I see this error log:

html2AttributedString: Html string parsing error: Error Area=NSCocoaErrorDomain Code=259 “The file couldn’t be opened as a result of it isn’t within the appropriate format.”

I’ve learn official doc and did not discover any pitfalls that would trigger the issue. Additionally I did not discover any comparable questions associated to getting NSAttributedString