Windows 10
Visual Studio 2022
Visual Micro - Release 22.11.28.15
Arduino 1.6/1.8
ATmega2560
avr_debugger (latest) installed from https://github.com/jdolinay/avr_debug

Using 'standard' Blink sketch.

When selecting Debug:Serial, everything works fine.
When selecting Debug:Hardware with GDB Stub, I get the error message in the Subject

======================
/*
Blink without Delay

Turns onand off a light emitting diode(LED) connected to a digital pin,
without using the delay() function.This means that other code can run at the
same time without being interrupted by the LED code.

The circuit :
-Use the onboard LED.
- Note : Most Arduinos have an on - board LED you can control.On the UNO, MEGA
and ZERO it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN
is set to the correct LED pin independent of which board is used.
If you want to know what pin the on - board LED is connected to on your
Arduino model, check the Technical Specs of your board at :
https://www.arduino.cc/en/Main/Products

created 2005
by David A.Mellis
modified 8 Feb 2010
by Paul Stoffregen
modified 11 Nov 2013
by Scott Fitzgerald
modified 9 Jan 2017
by Arturo Guadalupi

This example code is in the public domain.

http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay
*/

// constants won't change. Used here to set a pin number:
#ifdef VM_DEBUG_GDB
#include <app_api.h>
#include <avr_debugger.h>
#include "avr8-stub.h"
#endif
const int ledPin = LED_BUILTIN;// the number of the LED pin

// Variables will change:
int ledState = LOW;             // ledState used to set the LED

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0;        // will store last time LED was updated

// constants won't change:
const long interval = 1000;           // interval at which to blink (milliseconds)

void setup() {
#ifdef VM_DEBUG_GDB
    debug_init();
#endif
    // set the digital pin as output:
    pinMode(ledPin, OUTPUT);
}

void loop() {
#ifdef VM_DEBUG_GDB
    breakpoint();
#endif
    // here is where you'd put code that needs to be running all the time.

    // check to see if it's time to blink the LED; that is, if the difference
    // between the current time and last time you blinked the LED is bigger than
    // the interval at which you want to blink the LED.
    unsigned long currentMillis = millis();

    if (currentMillis - previousMillis >= interval) {
        // save the last time you blinked the LED
        previousMillis = currentMillis;

        // if the LED is off turn it on and vice-versa:
        if (ledState == LOW) {
            ledState = HIGH;
        }
        else {
            ledState = LOW;
        }

        // set the LED with the ledState of the variable:
        digitalWrite(ledPin, ledState);
    }
}

Hi Tim

Thank you for the reply!  I have tried both with the #define, and without and it still gives the same error.

Any additional insight is appreciated.

Micro Build results without #ifdef attached

THANK YOU!!!