Arduino 1.8.12 serial error

Hi Guys

I ''ve been playing with arduino for a while now and today updated to 1.8.12 from 1.8.10.

I uploaded my scetch and it gave me an error:

exit status 1
'Serial1' was not declared in this scope

I stipped the program completely and stil get the error, But when I return to 1.8.10 It compiles fine.

Seems like Serial1 is no longer used ?

The stripped down code:

void setup() {
  Serial.begin(9600);             //This turns on serial monitor on the USB
  Serial1.begin(9600); 
}

void loop() {
      Serial.println(" Hallo   ");

      Serial1.print("Hallo");

}

Any Ideas?

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you have Uno selected

Sorry,

I thought I was contributing to the topic I put the reply in, but now it seems I was just stupid enough to not notice the board had changed through the update,,

Sorry for the inconvenience.

This one can be closed