XamlDataProvider: formatProvider is null

[Art]

One project always throws this:

if (! TelerikUtils.IsInDesignMode ())
      Telerik.Windows.Documents.Utilities.Guard.ThrowExceptionIfNull<ITextBasedDocumentFormatProvider>(formatProvider, "formatProvider");

And nothing I can do with it.

References to:

Telerik.Windows.Documents;

Telerik.Windows.Documents.FormatProviders.Xaml;

Why is this happening? A new test project works perfect with the same code:

<StackPanel>
    <TextBox x:Name="Source" />
    <t:RadRichTextBox x:Name="PreviewBox" MinHeight="80" />
    <t:XamlDataProvider RichTextBox="{Binding ElementName=PreviewBox}"
    Xaml="{Binding ElementName=Source, Path=Text, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
</StackPanel>

 

[Art]

There is a problem with Prism. Some assemblies have to be connected in the library and in the main project. Strange. But it works.

[Petya]

Hello Art,

This behavior is related to RadRichTextBox's use of MEF. You can take a look at this help article for more information on the matter.

Regards,
Petya
Telerik