Trouble Flashing TMK firmware (IBM model F XT, Teensy 2.0, QMK Toolbox)

[gumilarganjar]

Hello, I found trouble flashing TMK firmware using QMK toolbox for my teensy-converted IBM model F XT. Flashing soarer's converter using this method was fine (currently typing on it), but boot-loop or flash-loop happened when I tried flashing TMK.

Here is the error:

*** Halfkay device connected: (null) (null) (16C0:0478:0120)
*** Attempting to flash, please don't remove device
>>> teensy_loader_cli -mmcu=atmega32u4 /Volumes/GG NVME/Download NVME/unimap.hex -v
    Teensy Loader, Command Line, Version 2.1
    Read "/Volumes/GG NVME/Download NVME/unimap.hex": 28390 bytes, 88.0% usage
    Found HalfKay Bootloader
    Programming...error writing to Teensy
 
Any help or explanation would be greatly appreciated.

[Sup]

Can you try to flash it from the commandline?

[gumilarganjar]

Unfortunately, my knowledge and experience in coding is almost nonexistent

Anyway, thankyou for the suggestion.

[Sup]

it's not coding. It's just putting your keyboard into bootloader mode and then using the command to compile with FLASH parameter with it.