Unable to upload to Nano Every

I have been unable to do anything with my new Every. I believe that the the drivers are in place but I get this message when trying to upload "Blink":

Arduino: 1.8.12 (Windows Store (Windows 10), Board: "Arduino Nano Every, None (ATMEGA4809)"

Sketch uses 1148 bytes (2%) of program storage space. Maximum is 49152 bytes.
Global variables use 22 bytes (0%) of dynamic memory, leaving 6122 bytes for local variables. Maximum is 6144 bytes.
An error occurred while uploading the sketch
avrdude: ser_open(): can't open device "\.\COM3": The system cannot find the file specified.

I get a steady green light and a blinking yellow on the board. Could it be the USB cable? How could I verify if this is the problem?

Is your Nano Every indeed on COM3? What happens in Windows device manager when you connect/disconnect de Nano Every?

Thank you for your help. No, COM3 does not show as being used used by Windows Device Manager with the Nano Every. It does recognize my Uno R3 when I plug it in though.

When using OFFICIAL boards each will assume a different COM port.
First make sure you have installed to board cores for the NANO EVERY.

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