Some of the formatting symbols (e.g. space, tab) don't affect the height of the paragraph. With the current implementation, changing the font size of a formatting symbol, which is first in the paragraph, changes its height as well.

The issue is a regression introduced with another fix, released in R2 2018.

The properties applied locally to the content are not preserved and used for the new content when the user changes the paragraph indent.

Workaround: Keep the properties in a variable and apply them after executing the command:

StyleDefinition style;

private void RadRichTextBox_CommandExecuted(object sender, CommandExecutedEventArgs e)
{
    if (e.Command is IncrementParagraphLeftIndentCommand)
    {
        this.radRichTextBox.CurrentEditingStyle.CopyPropertiesFrom(style);
    }
}
        
private void RadRichTextBox_CommandExecuting(object sender, Telerik.Windows.Documents.RichTextBoxCommands.CommandExecutingEventArgs e)
{
    if (e.Command is IncrementParagraphLeftIndentCommand)
    {
        style = new StyleDefinition(this.radRichTextBox.CurrentEditingStyle);
    }
}

Implement import and export of OpenDocument files (.odt).

Images with resolution higher than the image size currently visible in the document, are printed with low quality, as if the smaller image is scaled up.

The same is observed when an image is placed in header/footer and the document is zoomed in. Then the image should be rendered with better quality if available, but currently it isn't.

When a new document is created and GetStatisticsInfo is called on it, a NullReferenceException is thrown.

When a separate file for setting the xaml styles is used and then this file is merged in App.xaml the style cannot be found. 
As a workaround merge the resources directly in the App.xaml.

Fix available in LIB Version 2018.3.1029.

In MS Word, when track changes are enabled, the users can choose to show the revisions in balloons, similar to comments. Add such possibility in RadRichTextBox as well.

After merging a document into another one (or pasting it), some of the content is duplicated. The issue is a regression in R3 2018.

Import description lists: <dl>, <dt>, <dd> tags.

Possible way for implementation is with paragraphs with left margin.

Seems that the algorithm is not showing the appropriate results when a word has apostrophe. For example typing "etre" does not suggest "être".

A custom third-party spell checker library - NHunspell can be used. 
SDK Example demonstrating this approach can be found in our XAML-SDK portal:
https://github.com/telerik/xaml-sdk/tree/master/RichTextBox/NHunspellSpellChecking

Whenever the focus is on RadRichTextBox, the keyboard is displayed with Uppercase by Default. After inputting 2-3 characters in uppercase, it changes to lowercase and then alternates between uppercase and lower per character.

When a data provider is used, the designer does not show the RadRichTextBox content, that is shown with no problem at run time.

Workaround: The issue is with finding the format provider used by the data provider. This issue appears at design time only. The workaround is to manually set the format provider of the data provider:
        <telerik:HtmlDataProvider
            x:Name="htmlDataProvider"
            RichTextBox="{Binding ElementName=radRichTextBox, Mode=OneWay}"
            Html="&lt;h1&gt;Header3&lt;/h1&gt;">
            <telerik:HtmlDataProvider.FormatProvider>
                <telerik:HtmlFormatProvider />
            </telerik:HtmlDataProvider.FormatProvider>
        </telerik:HtmlDataProvider>

When RTF documents are imported simultaneously in different threads, sometimes ArgumentException with message "An item with the same key has already been added" is thrown with the following call stack:

at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.Add(String displayName, String name)
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.InitializeStyleDisplayNameToStyleNameDictionary()
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.get_StyleDisplayNameToStyleName()
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.TryGetStyleNamesByStyleName(String displayName, RadDocumentDefaultStyleInfo& defaultStyleInfo)
   at Telerik.Windows.Documents.FormatProviders.ReplaceStyleNameHandler.Replace(ReplaceStyleNameContext context)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStyleImporter.DoVisitText(RtfText text)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitElement(RtfElement element, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitGroupChildren(RtfGroup group, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStyleImporter.ImportStyleGroup(RtfGroup group)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStylesTable.FillStyle(RtfGroup group, StyleType type, Boolean isDefault)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStylesTable.DoVisitGroup(RtfGroup group)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitElement(RtfElement element, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitGroupChildren(RtfGroup group, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfStylesTable.ReadTable(RtfGroup group, RtfImportContext context)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfHandlers.RtfGroupHandlers.StylesTableHandler(RtfGroup group, RtfImportContext context)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfDocumentImporter.DoVisitGroup(RtfGroup group)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitElement(RtfElement element, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfElementIteratorBase.VisitGroupChildren(RtfGroup group, Boolean recursive)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfDocumentImporter.ImportRoot(RtfGroup rtfGroup)
   at Telerik.Windows.Documents.FormatProviders.Rtf.Import.RtfDocumentImporter.Import(Stream input, RtfImportSettings settings)
   at Telerik.Windows.Documents.FormatProviders.Rtf.RtfFormatProvider.Import(Stream input)
   at Telerik.Windows.Documents.FormatProviders.Rtf.RtfFormatProvider.Import(String input)

Fix available in LIB Version 2018.3.924.

Open a docx file in richtextbox, if numpages in headers do any subtraction, it can not display correctly. see the attached pictures for how to display in richtextbox and microsoft word 2016.

Steps to reproduce:
1. Insert a table into the document with borders enabled
2. Zoom out so the zoom level is below 100%
Expected behavior: The borders are always rendered at a minimum of 1px width, even if the calculated size is below 1 at the current zoom level (This is what Word does)
Actual behavior: Some of the borders do not render.