can't find the proper platform.txt

I have installed and programmed SAMD21

Now, I want to burn a bootloader on a brand new SAMD21. It does not work and I think this guy found a patch.

I want to patch platform.txt following his recommendation

I then installed 1.8.11 and that removed my old version 1.8.

I can't find platform.txt where are the SAMD21, well I did find it but it's old and doesn't even have SAMD and all my other boards in the file.

it's here
C:\Users\Jerome\CloudStation\Arduino\hardware\arduino\avr

I open it and it's

name=Arduino AVR Boards
version=1.8.2

So I am lost, I search my computer for platforms.txt and boards.txt, nothing

I am looking for all these files after installing "Arduino SAMD Boards (32-bit ARM Cortex-M0+)"

for example I have installed Sparkfun SAMD21 since I am programming it, but can't find the boards.txt where you see the board in the file.

I am confused.

I have fresh win10 and just installed 1.8.12 and installed Arduino SAMD Boards (32-bit ARM Cortex-M0+) and still can't find the proper boards.txt and platform.txt

hey Jerome, this is Jerome from the basement with the win10 laptop

here is the file
C:\Users\jerome\AppData\Local\Arduino15\packages\arduino\hardware\samd\1.8.6

to find it, you click files->preferences and click the bottom link with preferences.txt

1.8.6 is the samd version and not the arduino version

bought myself this 30$ Segger mini to program the bootloader. I was worth the 30$, got it working fairly easily with some little problems down the line but it was faster then my other method.