I realize this is a very old build (2011.1.545), but this is a new issue. Unfortunately, we are kind of stuck on this build as this was the one of the last one or two "legacy" builds. You significantly changed everything after that. We had spent a great deal of effort customizing stuff and tweaking styles, etc. and there were a lot of incompatibilities with the new architecture, so we just kind of stuck with this as mgmt didn't want to invest the time to do all that work again.
Anyways, I am positive this build was working probably in Sept 2014, so I'm not sure what I changed on my machine since then. Possibly installed .NET 4.5.1 and 4.5.2. Still on the same version of Visual Studio.
I started with a clean test app to make sure this had nothing to do with our customizations.
Nothing special in the XAML:
Title="MainWindow" Height="350" Width="525">
Nothing special in the C#:
/// Interaction logic for MainWindow.xaml
publicpartialclassMainWindow : RibbonWindow
So we are not overriding or customizing anything. All I have done from a stock WPF app is derive from Ribbon Window.
For some reason, when I run this app, at start up, I get a white rectangle that covers the entire window (frame and all). After approx. 1 second, it disappears and the window is normal. This is happening on ALL our apps that used the ribbon control.
It is ALSO happening on YOUR ribbon sample. So DEFINITELY, nothing I could possibly have done.
I can send you a screen shot of the white rectangle issue if needed.