can't upload Please help

I setted up my uno as a programmer first and when i tried to use it after it doesn't upload. Also the reset button also don't work. Anyone have any idea to fix this?

Error message

Arduino: 1.8.2 (Mac OS X), Board: "Arduino/Genuino Uno"

Sketch uses 4380 bytes (13%) of program storage space. Maximum is 32256 bytes.
Global variables use 481 bytes (23%) of dynamic memory, leaving 1567 bytes for local variables. Maximum is 2048 bytes.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00
Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

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Now I get this Error

Arduino: 1.8.2 (Mac OS X), Board: "Arduino/Genuino Uno"

/var/folders/pm/l7tr3mnj3qj90fpcnqv3zn1w0000gn/T//ccCH6xPf.ltrans0.ltrans.o: In function `main':
/Users/user/Desktop/Arduino.app/Contents/Java/hardware/arduino/avr/cores/arduino/main.cpp:35: undefined reference to `init'
collect2: error: ld returned 1 exit status
exit status 1
Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

u22hchoi:
Now I get this Error

Seems like you managed to mess up your installation of the Arduino IDE somehow. Uninstall and then reinstall and it should fix that problem.

As for your original problem, it's unlikely the Arduino re-install will help that. We need more information:

What exactly do you mean by "I setted up my uno as a programmer first"?

Did you check whether the Uno worked before you "setted up my uno as a programmer"?

I just ran into the same error message and found this topic with google!

I have a pro micro and my code is pretty simple:

void setup() {
  Serial.begin(250000);//set the serial communication baudrate

}

void loop() {
  Serial.print("ADC-Vpp: ");

}

What in the world...