Is there a reason why Visual Studio won\'t let me create a WPF window in a DLL project?
I \"solved\" it by creating a window in an Application Project and copying it
What do you mean that Visual Studio won't let you create a WPF window in a DLL project? Do you mean that if you right click the project, there is no option to add a Window there?
If that is the case, I think that means that you created a project type that isn't a WPF project type. I encountered something similar a while back when I wanted to upgrade a WinForms project to use WPF instead - see this question for more information.