error message.

Arduino: 1.8.5 (Windows 10), Board: “Arduino/Genuino Uno”

Build options changed, rebuilding all
In file included from C:\Users\Dennis\Documents\Arduino\sketch_may22b\sketch_may22b.ino:2:0:

C:\Program Files (x86)\Arduino\libraries\Keyboard\src/Keyboard.h:29:2: warning: #warning “Using legacy HID core (non pluggable)” [-Wcpp]

#warning “Using legacy HID core (non pluggable)”

^

C:\Users\Dennis\Documents\Arduino\sketch_may22b\sketch_may22b.ino:4:18: warning: character constant too long for its type

Keyboard.println(‘Written by GeeDees Arduino’);

^

C:\Users\Dennis\Documents\Arduino\sketch_may22b\sketch_may22b.ino: In function ‘void setup()’:

sketch_may22b:4: error: ‘Keyboard’ not found. Does your sketch include the line ‘#include <Keyboard.h>’?
Keyboard.println(‘Written by GeeDees Arduino’);

^

exit status 1
‘Keyboard’ not found. Does your sketch include the line ‘#include <Keyboard.h>’?

This report would have more information with
“Show verbose output during compilation”
option enabled in File → Preferences.

Dennis - read how to use the forum to post questions... we lack all the context to be able to provide meaningful guidance and would have to run into hypothesis of what your code is or the libraries you use etc....

help us help you...

C:\Users\Dennis\Documents\Arduino\sketch_may22b\sketch_may22b.ino:4:18: warning: character constant too long for its type

 Keyboard.println('Written by GeeDees Arduino');

                  ^

Use double-quotes around string constants. Single quotes go around character constants which can only hold 1 or 2 characters.

GeeDeexd:
C:\Users\Dennis\Documents\Arduino\sketch_may22b\sketch_may22b.ino: In function ‘void setup()’:

sketch_may22b:4: error: ‘Keyboard’ not found. Does your sketch include the line ‘#include <Keyboard.h>’?
Keyboard.println(‘Written by GeeDees Arduino’);

^

exit status 1
‘Keyboard’ not found. Does your sketch include the line ‘#include <Keyboard.h>’?

The Arduino Uno board is not compatible with the Keyboard library, which is why you got this error.
From Keyboard - Arduino Reference

These core libraries allow the 32u4 and SAMD based boards (Leonardo, Esplora, Zero, Due and MKR Family) to appear as a native Mouse and/or Keyboard to a connected computer.

Another popular board with native USB is the Pro Micro (or Micro).

pert:
The Arduino Uno board is not compatible with the Keyboard library, which is why you got this error.
From https://www.arduino.cc/reference/en/language/functions/usb/keyboard/Another popular board with native USB is the Pro Micro (or Micro).

I have the pro micro

Then you need to select Tools > Board > Arduino/Genuino Micro.

pert:
Then you need to select Tools > Board > Arduino/Genuino Micro.

Now I get this message

Arduino: 1.8.5 (Windows 10), Board: "Arduino/Genuino Micro"

Build options changed, rebuilding all
Sketch uses 5192 bytes (18%) of program storage space. Maximum is 28672 bytes.
Global variables use 254 bytes (9%) of dynamic memory, leaving 2306 bytes for local variables. Maximum is 2560 bytes.

avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
avrdude: butterfly_recv(): programmer is not responding
Found programmer: Id = "þ"; type = ¸
Software Version = h.

…and now we’re right back to your previous thread:

pert:
…and now we’re right back to your previous thread:
http://forum.arduino.cc/index.php?topic=549118

but my code is
#include <Keyboard.h>

void setup() {

Keyboard.println(“Written by GeeDees Arduino”);
}

void loop() {
// put your main code here, to run repeatedly:

}

The code is irrelevant. You're encountering an upload error.

pert:
The code is irrelevant. You're encountering an upload error.

How do I fix the upload error?

Can you provide a link to your exact board? You might need to install this possibly