Pro Micro USB-C (ATmega32U4) programming error with Arduino IDE 2.0.0

I recently downloaded Arduino IDE 2.0.0 while waiting for my Pro Micro board. Installed the Pro Micro according to the instructions on my Mac Studio M1.

Then for days I’ve been beating my head again a “wall” with the Pro Micro while trying to load & run Pro_Micro_RX-TX_Blinky. I would always get the following upon trying to upload the sketch:

Sketch uses 5130 bytes (17%) of program storage space. Maximum is 28672 bytes.

Global variables use 430 bytes (16%) of dynamic memory, leaving 2130 bytes for local variables. Maximum is 2560 bytes.

Connecting to programmer: .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

avrdude: butterfly_recv(): programmer is not responding

Found programmer: Id = “”; type =

Software Version = .; Hardware Version = .

avrdude: butterfly_recv(): programmer is not responding

avrdude: butterfly_recv(): programmer is not responding

avrdude: error: buffered memory access not supported. Maybe it isn’t

a butterfly/AVR109 but a AVR910 device?

avrdude: initialization failed, rc=-1

Double check connections and try again, or use -F to override

this check.

avrdude: butterfly_recv(): programmer is not responding

avrdude: error: programmer did not respond to command: leave prog mode

avrdude: butterfly_recv(): programmer is not responding

avrdude: error: programmer did not respond to command: exit bootloader

Failed uploading: uploading error: exit status 1

Finally, I discovered that if I double-tap the reset button just as the sketch was beginning to upload (after compiling) I would have success in the upload and get this message:

Sketch uses 5130 bytes (17%) of program storage space. Maximum is 28672 bytes.

Global variables use 430 bytes (16%) of dynamic memory, leaving 2130 bytes for local variables. Maximum is 2560 bytes.

Connecting to programmer: .

Found programmer: Id = “CATERIN”; type = S

Software Version = 1.0; No Hardware Version given.

Programmer supports auto addr increment.

Programmer supports buffered memory access with buffersize=128 bytes.

Then I tried running the same Blinky sketch on my MacBook Air M2 which was still running Arduino IDE 1.8.19 using the same Pro Micro board. Complete success loading and running the sketch, making changes and re-loading the sketch, all without any complications what so ever. Uploads happened without any messaging.

Going back to the Mac Studio I downloaded and installed Arduino IDE 1.8.19. Again the Pro Micro installed all sketches with out any problems.

Bottom line: There’s something amiss with the Arduino 2.0.0 IDE and the Pro Micro.

Stick with 1.8.19, it’s a lot more stable.