OS X Hangs

Re: arduino-1.8.9-macosx.zip
OS X Maverick 10.95
OS X High Sierra
arduino NANO old bootloader/ch340 driver

This is the latest release to be able to compile/upload the blink sketch on referenced platform's.
The following code compiles and sets TX led, but then hangs OS X when launching serial plotter:

void setup(){
Serial.begin(115200); // setup serial connection
void loop(){
int val = analogRead(A0); // read analog pin
Serial.println(val); // write analog value to serial port

The arduino nano is now crippled and connot compile/upload the blink sketch.

Please provide a way to restore blink and resolve OS X from being shut down in this way.