Collect2.exe error

Executing task in folder argb: C:\Users\Max\.platformio\penv\Scripts\platformio.exe run <
Processing uno (platform: atmelavr; board: uno; framework: arduino)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/atmelavr/uno.html
PLATFORM: Atmel AVR (3.4.0) > Arduino Uno
HARDWARE: ATMEGA328P 16MHz, 2KB RAM, 31.50KB Flash
DEBUG: Current (avr-stub) On-board (avr-stub, simavr)
PACKAGES: 
 - framework-arduino-avr 5.1.0
 - toolchain-atmelavr 1.70300.191015 (7.3.0)
LDF: Library Dependency Finder -> https://bit.ly/configure-pio-ldf
LDF Modes: Finder ~ chain, Compatibility ~ soft
Found 6 compatible libraries
Scanning dependencies...
Dependency Graph
|-- <Adafruit NeoPixel> 1.10.3
Building in release mode
Linking .pio\build\uno\firmware.elf
C:\Users\Max\AppData\Local\Temp\cc8zFjJd.ltrans0.ltrans.o: In function `main':
<artificial>:(.text.startup+0x86): undefined reference to `setup'
<artificial>:(.text.startup+0x8e): undefined reference to `loop'
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\uno\firmware.elf] Error 1
============================================================================================================================================= [FAILED] Took 0.88 seconds =============================================================================================================================================
The terminal process "C:\Users\Max\.platformio\penv\Scripts\platformio.exe 'run'" terminated with exit code: 1.

Terminal will be reused by tasks, press any key to close it.

I already tried to google my way out, but i cant find a working fix for this. I get this error when i try to verify or upload any code. It also looks like its generating “problems” in code wich is already able to run on a arduino.
Besides this it realy likes german, everytime i launch the programm it asks to get restarted to install the german language pack, wich i always uninstall because errors in german make even less sence than in english

The working code wich trows some kind of include error:

// A basic everyday NeoPixel strip test program.
// NEOPIXEL BEST PRACTICES for most reliable operation:
// - Add 1000 uF CAPACITOR between NeoPixel strip's + and - connections.
// - MINIMIZE WIRING LENGTH between microcontroller board and first pixel.
// - NeoPixel strip's DATA-IN should pass through a 300-500 OHM RESISTOR.
// - AVOID connecting NeoPixels on a LIVE CIRCUIT. If you must, ALWAYS
//   connect GROUND (-) first, then +, then data.
// - When using a 3.3V microcontroller with a 5V-powered NeoPixel strip,
//   a LOGIC-LEVEL CONVERTER on the data line is STRONGLY RECOMMENDED.
// (Skipping these may work OK on your workbench but can fail in the field)
//#include <Arduino.h>
#include <Adafruit_NeoPixel.h>
#idef __AVR__
#include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif
// Which pin on the Arduino is connected to the NeoPixels?
// On a Trinket or Gemma we suggest changing this to 1:
#define LED_PIN    11
// How many NeoPixels are attached to the Arduino?
#define LED_COUNT 31
// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, NEO_GRB + NEO_KHZ800);
/* Argument 1 = Number of pixels in NeoPixel strip
 Argument 2 = Arduino pin number (most are valid)
 Argument 3 = Pixel type flags, add together as needed:
   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products) */
void setup()  { //function -- runs once at startup --------------------------------
int CounterA = 0;
int CounterB = 0;
int ButtonA = 3;
int ButtonB = 4;
int Timer1 = 50;
int Timer2 = 125;
//int tempCounter = 0;
int ButtonA = digitalRead(3);
int ButtonB = digitalRead(4);
int state = Serial.parseInt();
  CounterA = CounterA +1;
  Serial.begin(9600);
  while (!serial);
  Serial.print("Reset");
  // These lines are specifically to support the Adafruit Trinket 5V 16 MHz.
  // Any other board, you can remove this part (but no harm leaving it):
#if defined(__AVR_ATtiny85__) && (F_CPU == 16000000)
  clock_prescale_set(clock_div_1);
#endif
  // END of Trinket-specific code.
  strip.begin();           // INITIALIZE NeoPixel strip object (REQUIRED)
  strip.show();            // Turn OFF all pixels ASAP
  strip.setBrightness(191); // Set BRIGHTNESS to 75% 191
  pinMode(3, INPUT);
  pinMode(4, INPUT);
//  pinMode(7, OUTPUT);
}
void loop() {
  Serial.println("↓");
  Serial.print("CounterA: ");    //debug
  Serial.println(CounterA);
  Serial.print("CounterB: ");
  Serial.println(CounterB);
    if(Serial.available())  {
      int sate = Serial.parseInt();
      if (state == 1) {
        Serial.println("Serial In recived");
        CounterA = CounterA +1;
      }
      if (state == 2)  {
        CounterB = CounterB +1;
      }
    }
  if(ButtonB == HIGH) {
    CounterB = CounterB +1;
  }
  if(CounterB == (2)) {
    CounterB = CounterB -2;
    delay(5000);
  }
  if(CounterB == (1)) {
    rainbow(25);
    }
  if(ButtonA == HIGH) {
    CounterA = CounterA +1;
  //  tempCounter = tempCounter +1;
  }
    //tempCounter = tempCounter -1;
    if(CounterB == (0)) {
      if(CounterA == (0)) {
        colorWipe(strip.Color(  0,   0,   0),Timer1); //RBG  
        CounterA = CounterA +1;
     }
      if(CounterA == (2)) {
        colorWipe2(strip.Color(   0, 255, 150),Timer1);  //RBG
        Serial.print("Farbwechsel, 0, 255, 150");
        CounterA = CounterA +1;
     }
      if(CounterA == (3)) {
     }
      if(CounterA == (4)) {
        colorWipe(strip.Color(   0, 255,  20),Timer1); //RBG
        Serial.print("Farbwechsel, 0, 255, 20");
     }  
      if(CounterA == (6)) {
        colorWipe2(strip.Color(255,   0,   0),Timer1);  //RBG
        Serial.println("Farbwechsel, 255, 0, 0");
     }
      if(CounterA == (8)) {
        colorWipe(strip.Color(  0, 255,   0),Timer1);  //RBG
        Serial.println("Farbwechsel, 0, 255, 0");
     }
      if(CounterA == (10)) {
        colorWipe2(strip.Color(  0,   0, 255),Timer1);  //RBG
        Serial.println("Farbwechsel, 0, 0, 255");
     }
      if(CounterA == (12)) {
        colorWipe(strip.Color(255, 255,   0),Timer1);  //RBG
        Serial.println("Farbwechsel, 255, 255, 0");
     }
      if(CounterA == (14)) {
        colorWipe2(strip.Color(  0, 255, 255),Timer1);  //RBG
        Serial.println("Farbwechsel, 0, 255, 255");
     }
      if(CounterA == (16)) {
        colorWipe(strip.Color(255,   0, 255),Timer1);  //RBG
        Serial.println("Farbwechsel, 255, 0, 255");
     }
      if(CounterA == (18)) {
        colorWipe2(strip.Color(255, 255, 255),Timer1);  //RBG
        Serial.println("Farbwechsel 255 255 255");
     }
      if(CounterA == (20)) {
        colorWipe(strip.Color(  0, 150, 75),Timer1);  //RBG
     }
      if(CounterA == (22))  {
        theaterChase(strip.Color(  0, 255, 150),Timer2);  //RBG
     }
      if(CounterA ==(24))  {
        theaterChase2(strip.Color(  0, 255, 150),Timer2);  //RBG
     }
      if(CounterA ==(12)) {
        CounterA = CounterA -12;   //Return to 0
     }
    }
  }
  // Do a theater marquee effect in various colors...
  //theaterChase(strip.Color(0, 255, 0), 75); // Green, half brightness
  //  theaterChase(strip.Color(255,   0,   0), 75); // Red, half brightness
  //  theaterChase(strip.Color(  0,   0, 255), 75); // Blue, half brightness
  // rainbow(25);
  // rainbowCycle(30);// Flowing rainbow cycle along the whole strip
  // theaterChaseRainbow(50); // Rainbow-enhanced theaterChase variant
  // colorWave(50);
/*  digitalWrite(7, HIGH);    //debug
  delay(100);
  digitalWrite(7, LOW);*/
void update() {
   Serial.println("update");   //debug
   if(ButtonA == HIGH) {
    CounterA = CounterA +1;
    //tempCounter = tempCounter +1;
  }
   if(ButtonB == HIGH) {
    CounterB = CounterB +1;
    //tempCounter = tempCounter +1;
  }
   if(ButtonB == HIGH) {
    CounterB = CounterB +1;
  }
}
// Some functions of our own for creating animated effects -----------------
// Fill strip pixels one after another with a color. Strip is NOT cleared
// first; anything there will be covered pixel by pixel. Pass in color
// (as a single 'packed' 32-bit value, which you can get by calling
// strip.Color(red, green, blue) as shown in the loop() function above),
// and a delay time (in milliseconds) between pixels.
void colorWipe(uint32_t color, int wait) {
  for (int i = 0; i < strip.numPixels(); i++) { // For each pixel in strip...
    strip.setPixelColor(i, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}
void colorWipe2(uint32_t color, int wait) {
  for (int i = 0; i < strip.numPixels(); i++) { // For each pixel in strip...
    strip.setPixelColor(strip.numPixels() - i-1, color);         //  Set pixel's color (in RAM)
    strip.show();                          //  Update strip to match
    delay(wait);                           //  Pause for a moment
  }
}
// Slightly different, this makes the rainbow equally distributed throughout
void rainbowCycle(uint8_t wait) {
  uint16_t i, j;
  for (j = 0; j < 256 * 5; j++) { // 5 cycles of all colors on wheel
    for (i = 0; i < strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel(((i * 256 / strip.numPixels()) + j) & 255));
    }
    strip.show();
    delay(wait);
  }
}
uint32_t Wheel(byte WheelPos) {
  if (WheelPos < 85) {
    return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  } else if (WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else {
    WheelPos -= 170;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
}
/**
----------ColorWave---------
 */
void colorWave(uint8_t wait) {
  int i, j, stripsize, cycle;
  float ang, rsin, gsin, bsin, offset;
  static int tick = 0;
  stripsize = strip.numPixels();
  cycle = stripsize * 5; // times around the circle...
  while (++tick % cycle) {
    offset = map2PI(tick);
    for (i = 0; i < stripsize; i++) {
      ang = map2PI(i) - offset;
      rsin = sin(ang);
      gsin = sin(2.0 * ang / 3.0 + map2PI(int(stripsize / 6)));
      bsin = sin(4.0 * ang / 5.0 + map2PI(int(stripsize / 3)));
      strip.setPixelColor(i, strip.Color(trigScale(rsin), trigScale(gsin), trigScale(bsin)));
    }
    strip.show();
    delay(wait);
  }
}
/**
   Scale a value returned from a trig function to a byte value.
   [-1, +1] -> [0, 254]
   Note that we ignore the possible value of 255, for efficiency,
   and because nobody will be able to differentiate between the
   brightness levels of 254 and 255.
*/
byte trigScale(float val) {
  val += 1.0; // move range to [0.0, 2.0]
  val *= 127.0; // move range to [0.0, 254.0]
  return int(val) & 255;
}
/**
   Map an integer so that [0, striplength] -> [0, 2PI]
*/
float map2PI(int i) {
  return PI * 2.0 * float(i) / float(strip.numPixels());
}
// Theater-marquee-style chasing lights. Pass in a color (32-bit value,
// a la strip.Color(r,g,b) as mentioned above), and a delay time (in ms)
// between frames.
void theaterChase(uint32_t color, int wait) {
  for (int a = 0; a < 10; a++) { // Repeat 10 times...
    for (int b = 0; b < 3; b++) { //  'b' counts from 0 to 2...
      strip.clear();         //   Set all pixels in RAM to 0 (off)
      // 'c' counts up from 'b' to end of strip in steps of 3...
      for (int c = b; c < strip.numPixels(); c += 3) {
        strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
      }
      strip.show(); // Update strip with new contents
      delay(wait);  // Pause for a moment
    }
  }
  a = a-10;
}
void theaterChase2(uint32_t color, int wait)   {
  for (int a = 0; a < 10; a++) { // Repeat 10 times...    default 0, 10
    for (int b = 0; b < 4; b++) { //  'b' counts from 0 to 2...   default 0, 3
      strip.clear();         //   Set all pixels in RAM to 0 (off)
      // 'c' counts up from 'b' to end of strip in steps of 3...
      for (int c = b; c < strip.numPixels(); c += 3) {
        strip.setPixelColor(strip.numPixels() -c-1, color); // Set pixel 'c' to value 'color'    -1 fix for the first led not chaning
      }
      strip.show(); // Update strip with new contents
      delay(wait);  // Pause for a moment
    }
  }
}
// Rainbow cycle along whole strip. Pass delay time (in ms) between frames.
void rainbow(int wait) {
  // Hue of first pixel runs 5 complete loops through the color wheel.
  // Color wheel has a range of 65536 but it's OK if we roll over, so
  // just count from 0 to 5*65536. Adding 256 to firstPixelHue each time
  // means we'll make 5*65536/256 = 1280 passes through this outer loop:
  for (long firstPixelHue = 0; firstPixelHue < 5 * 65536; firstPixelHue += 256) {
    for (int i = 0; i < strip.numPixels(); i++) { // For each pixel in strip...
      // Offset pixel hue by an amount to make one full revolution of the
      // color wheel (range of 65536) along the length of the strip
      // (strip.numPixels() steps):
      int pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());
      update();
      // strip.ColorHSV() can take 1 or 3 arguments: a hue (0 to 65535) or
      // optionally add saturation and value (brightness) (each 0 to 255).
      // Here we're using just the single-argument hue variant. The result
      // is passed through strip.gamma32() to provide 'truer' colors
      // before assigning to each pixel:
      strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue)));
      update();
    }
    strip.show(); // Update strip with new contents
    delay(wait);  // Pause for a moment
  }
}
// Rainbow-enhanced theater marquee. Pass delay time (in ms) between frames.
void theaterChaseRainbow(int wait) {
  int firstPixelHue = 0;     // First pixel starts at red (hue 0)
  for (int a = 0; a < 30; a++) { // Repeat 30 times...
    for (int b = 0; b < 3; b++) { //  'b' counts from 0 to 2...
      strip.clear();         //   Set all pixels in RAM to 0 (off)
      // 'c' counts up from 'b' to end of strip in increments of 3...
      for (int c = b; c < strip.numPixels(); c += 3) {
        // hue of pixel 'c' is offset by an amount to make one full
        // revolution of the color wheel (range 65536) along the length
        // of the strip (strip.numPixels() steps):
        int      hue   = firstPixelHue + c * 65536L / strip.numPixels();
        uint32_t color = strip.gamma32(strip.ColorHSV(hue)); // hue -> RGB
        strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
      }
      strip.show();                // Update strip with new contents
      delay(wait);                 // Pause for a moment
      firstPixelHue += 65536 / 90; // One cycle of color wheel over 90 frames
    }
  }
}

This is likely a VSCode popup and has nothing to do with PlatformIO, which is a VSCode plugin.

Where is this program file stored, and under wich filename?

I based it on the example code wich i found on github, and put some code in to make the colours change. But now i cant even upload

Create a file src/main.cpp with the minimum

#include <Arduino.h>

void setup(){}
void loop(){}

content. Does it compile and upload now?