Color (transparency) problem in ArcGIS Pro 3.4 when using WindowsFormsHost in a DockPane

Question

Hi,

We host Windows Forms controls inside of a WindowsFormsHost in a DockPane in ArcGIS Pro and everything
has worked fine until version 3.4. When the pane is undocked it looks normal but when it's docked,
text color of controls inside the WindowsFormsHost (for example tree view's tree node text, textbox etc..) changes and becomes almost invisible when using light mode in Windows.

This problem occurs when using ArcGIS Pro 3.4 and Windows 11.

I have attached a sample AddIn for Pro 3.4 and some screenshots.

Best regards,

Kęstutis

P.S. The issue seems to be the same as with .NET9rc2 new fluent themes (WindowsFormsHost rendering broken with new fluent themes in .NET 9 · Issue #10044 · dotnet/wpf). As ESRI seems to use ActiPro software's themes we are quite confident they are the source of the issue, so ESRI, please fix this ASAP.

docked.png

ProAppModule1.zip

undocked.png

BenWilkersonJC_1-1738093401587.png

TimHaverlandNOAA_0-1738092989883.png

Screenshot 2025-01-28 131357.png

MichaelGrossman · Answer

Hi Kris.

We are trying to ship the 3.4.1 patch sometime in the next few weeks.

--Michael

KrisCulin · Answer

@MichaelGrossman

Do you know if there is a code fix that a configuration can use until a patch is released?  We are in the process of doing final testing on a new release and we cannot wait until you release a patch (February, right?).

Thanks.

Kris

MichaelGrossman · Answer

Hi Kęstutis.

We are tracking this issue as BUG-000172334: In Windows 11, content in a WindowsFormsHost is miscolored or invisible when rendered in a docked dock pane

And we are targeting a fix for the 3.4.1 Patch Release.

As you may have found, there are a few workarounds. Switching to dark theme, floating the dock pane, unpinning the dock pane, or connecting over remote desktop will make the problem go away.

Please accept our apologies for the problem and its impact on your users.

Michael