Macbook connection to Arduino Uno


I seem to have an issue with my macbook connecting to the Uno.

When I click to upload a sketch I get an error as per below.

To solve this, I found that if I keep clicking upload, it somehow connects and uploads the sketch.

I also found that when the Uno is connected to the Macbook, it consistently resets after about 5 seconds. What it seems like is that the power to the board is turning on and off every 5 seconds or so.

The only way for me to then use the board is to remove the USB from the macbook and plug it into a USB power source or alternative.

Does anyone know how to fix this?


"Arduino: 1.8.13 (Mac OS X), Board: “Arduino Uno”

Sketch uses 2668 bytes (8%) of program storage space. Maximum is 32256 bytes.
Global variables use 32 bytes (1%) of dynamic memory, leaving 2016 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can’t open device “/dev/cu.usbmodem14401”: Resource busy
Problem uploading to board. See for suggestions.

This report would have more information with
“Show verbose output during compilation”
option enabled in File → Preferences."