Overflow exception in ReadLookAheadCharacter in WPF-Samples-main\WPF-Samples\Sample Applications\HtmlToXamlDemo

I have an WPF application in which i am using the classes (htmlLexicalAnalyzer.cs, HtmlToXAMLConverter, etc.) from the sample application HtmlToXAMLDemo (the main repo).

I have changed the namespace of that classes for mine only.

Then in my physical pc is working correctly (no errors nor exceptions).

Then I create an MSI and deploy my WPF application to a new clean and fresh pc (a virtual machine). After installation I execute it and I get the below exception:

System.OverflowException: Arithmetic operation resulted in an overflow.
at myApp.Converters.HtmlConverter.HtmlLexicalAnalyzer.ReadLookAheadCharacter()
at myApp.Converters.HtmlConverter.HtmlLexicalAnalyzer.GetNextCharacter()
at myApp.Converters.HtmlConverter.HtmlLexicalAnalyzer.GetNextTagToken()
at myApp.Converters.HtmlConverter.HtmlParser.ParseHtmlContent()
at myApp.Converters.HtmlConverter.HtmlToXamlConverter.ConvertHtmlToXaml(String htmlString, Boolean asFlowDocument)
at myApp.UI.HtmlRichTextBoxBehavior.OnValueChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)

It looks like there is something wrong in ReadLookAheadCharacter that is causing this exception in some particular scenario like mine.

Please, could you have a look at it and fix it? Thanks in advance.