I recently re-visited this project, and found that, amongst other things, it would no longer run up. Clearly something had changed, and it was a while until I realised what. The error I was getting was this:
The App.Xaml looked like this:
<Application x:Class="TFSUtils.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:vm="clr-namespace:TFSUtils.ViewModel" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" StartupUri="MainWindow.xaml" mc:Ignorable="d">
Solution
I finally realised that I must have copied the MainWindow.Xaml into the Views folder as a last minute cleanup. The fix was very simple:
<Application x:Class="TFSUtils.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:vm="clr-namespace:TFSUtils.ViewModel" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" StartupUri="View/MainWindow.xaml" mc:Ignorable="d">
Conclusion
So, there you go: long untouched and untested code just spontaneously breaks! Magic.