Serial monitor problem

Here my error :

Arduino: 1.8.5 (Linux), Board: "Arduino/Genuino Uno"
Sketch uses 2052 bytes (6%) of program storage space. Maximum is 32256 bytes.
Global variables use 184 bytes (8%) of dynamic memory, leaving 1864 bytes for local variables. Maximum is 2048 bytes.
Serial monitor not available while plotter is open

And my code :

void setup() {
Serial.begin(9600);
pinMode(10, INPUT);

}

void loop() {
boolean a=digitalRead(10);
Serial.print(a);
Serial.end();
}

I've tried to change external ports and there is no connections on my card :frowning: It's the lastet version of Arduino)

Thanks for yout help it's my first topic :slight_smile:

And what is the problem exactly?

.

On my Arduino with nothing connected to the pins, it prints:

1

Boom44:
Serial monitor not available while plotter is open

Close the Serial Plotter window before opening Serial Monitor.