WinRT applications are applications that use Windows Runtime framework. More specifically, these are Windows Store and Universal Windows Platform (UWP) applications.
Note that dotTrace is unable to profile a UWP application if it uses .NET native tool chain. To profile such an application, you should disable the Compile with .NET Native tool chain option in Visual Studio (via the menu ) and rebuild the project.
In order to profile a WinRT application, you should specify the following parameter:
The list of all WinRT applications installed in your system.
Here you should choose the application you are going to profile.