Port failed to open - already in use? on iMac

I must have done something to cause this as I got an okay before. I have an iMac with macOS Sonoma 14.5. My device is a laser Aufero LU2-4-SF.

You most likely need to select the correct COM port from the drop down menu in the laser window.

If none of the ports work, try right-clicking the Devices button to refresh the list of ports, or powering your laser off, restarting LightBurn, and powering the laser back on.

If that doesn’t help, this could be a USB issue.