foreach (var paragraph in this.flowDocument.EnumerateChildrenOfType<Paragraph>())
{
    if (paragraph.Properties.HangingIndent.HasLocalValue)
    {
        Run run = paragraph.EnumerateChildrenOfType<Run>().Where(r => r.Text == "\t").FirstOrDefault();

        if (run != null)
        {
            paragraph.TabStops = paragraph.TabStops.Insert(new Telerik.Windows.Documents.Flow.Model.Styles.TabStop(paragraph.Properties.HangingIndent.LocalValue.Value));
        }

    }
}

        public MainWindow()
        {
            InitializeComponent();

            Telerik.Windows.Documents.Flow.FormatProviders.Html.HtmlFormatProvider provider = new Telerik.Windows.Documents.Flow.FormatProviders.Html.HtmlFormatProvider();
            RadFlowDocument document = provider.Import("<html><body><h1>My First Heading</h1><p>My first paragraph.</p></body></html>");
        }

System.IO.FileNotFoundException: 'Could not load file or assembly 'System.Text.Encoding.CodePages, Version=7.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. The system cannot find the file specified.'

	<ItemGroup>
		<PackageReference Include="Telerik.Windows.Documents.Flow" Version="2024.2.426" />
		<PackageReference Include="System.Text.Encoding.CodePages" Version="7.0.0" />
	</ItemGroup>
	<ItemGroup>
		<FunctionsPreservedDependencies Include="System.Text.Encoding.CodePages.dll" />
	</ItemGroup>

RadFlowDocument flowDocument;
using (Stream str = new FileStream("input.docx", FileMode.OpenOrCreate))
{
    MemoryStream ms = new MemoryStream();
    str.CopyTo(ms);
    ms.Seek(0, SeekOrigin.Begin);

    using (ZipArchive archive = ZipArchive.Update(ms, null))
    {
        var zipEntries = archive.Entries;

        // Skip glossary on importfor (int i = zipEntries.Count() - 1; i >= 0; i--)
        {
            var entry = zipEntries.ElementAt(i);
            string entryName = entry.FullName;
            if (Regex.IsMatch(entryName, @"\[trash\]"))
            {
                entry.Delete();
            }
        }
    }
}