MC3000 (Invalid character) error in the content of a control containing accented characters for a user control.

[Perpete]

Description

In a user control, if a Label control has an accented character in its content (à - â - ä - é - è - ê etc...), we get an error MC3000: XML 'There is an invalid character in the given encoding.

For a normal application project, the problem is not present.

Reproduction Steps

• Create a user control.
• Added a label control
• Added an accented character in the Content property (ex:Labelé).
• Generate the solution
• The error is reported

You can test with the attached example

TestUserControl.zip

Expected behavior

No more errors detected like in a normal WPF application.

Actual behavior

Error MC3000: XML 'There is an invalid character in the given encoding.

Regression?

With framework 4.8 there was no problem with my user control.

Known Workarounds

I don't know.

Impact

Unable to use my user control with .net 9.

Configuration

Visual studio 2022 Version 17.12.1
.net 9
Program in VB.

Other information

No response

[miloush]

This is a designer issue, please file feedback using Visual Studio.

It might also help if you change your file encoding to UTF-8.

[Perpete]

Thanks for your reply.
I just sent my comments from visual studio.

[himgoyalmicro]

@Perpete If we use the encoded value for e, viz é then it works fine as well.

<Label Content="Label&#233;" HorizontalAlignment="Center" Margin="0,60,0,0" VerticalAlignment="Top" Width="110" Background="White" FontSize="24" FontWeight="Bold"/>
<TextBox Text="TextBox&#233;" HorizontalAlignment="Left" Height="40" Margin="125,130,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="115" FontSize="24" FontWeight="Bold"/>
<Button Content="Button&#233;" HorizontalAlignment="Left" Height="40" Margin="125,200,0,0" VerticalAlignment="Top" Width="115" FontSize="24" FontWeight="Bold"/>

[Perpete]

@himgoyalmicro Thanks for your workaround.

I hope this issue will be fixed in the future.
The problem is only in a user control.