I'm trying to set up a simple LED blinking example on a Raspberry Pi 4 running Windows IoT Core. The official docs mention using GpioController, but I'm getting a COMException when calling OpenPin. Has anyone encountered this issue?

Make sure you have the correct capability declared in the app manifest:

<DeviceCapability Name="gpio" />

Also, verify that the pin number matches the board's layout. Pin 5 works for me.

If you're using Visual Studio, check that the target architecture is set to ARM64 for the Pi 4. x86 builds will not work and can cause that exception.