vrdude: ser_open(): can't open device

Using Arduino Installation & Troubleshooting
#1

Running:Arduino Uno on MacOS Catalina 10.15

I was able to run my arduino for some period, but when i was trying to connect the serial port to the Processing IDE the port /dev/tty.usbserial-1420 disappeared from the Port communication in the Arduino IDE, and i can't upload my sketch anymore because i get that error back.

If someone could help me with some tips to re-establish the connection for the USB port would be a great help.

#2

I'm not a Mac user.

Did you close the processing IDE?

A serial port can only be used by one application at a time.

#3