Arduino for STM32

... to me, looks like the 2 PC's have differences ... I would expect that.

I have 3 machines here that the IDE menus look different (different IDE versions) and different core versions installed over time.

Remember, the IDE looks across the user storage space and builds Examples, Boards, and sub-menus dynamically.

READ this:
https://www.arduino.cc/en/guide/environment

and then note:

Last revision 2015/09/07 by SM

Documentation can take a long time to be updated... a very long time.

stan wrote: ↑Mon Jan 25, 2021 8:54 pm I followed the links and the results are as in previous post.
Screen Shot 2021-01-25 at 3.34.37 PM.png
This what is missed and I can't fix that.

I've just installed Roger's Clark core and it works. It's just download, unzip, change folder name, move.

I did 3 things = marked.

You
It's just download, unzip, change folder name, move.
1. It's just download,
2. unzip,
3. change folder name, move.
Me
1. It's just download,
2. unzip to desktop, copy folder
3. paste to arduino hardware

No change folder name
move = paste to arduino hardware ?

stan wrote: ↑Tue Jan 26, 2021 2:01 am Screen Shot 2021-01-25 at 8.50.57 PM.png

I did 3 things = marked.

You
It's just download, unzip, change folder name, move.
1. It's just download,
2. unzip,
3. change folder name, move.
Me
1. It's just download,
2. unzip to desktop, copy folder
3. paste to arduino hardware

No change folder name
move = paste to arduino hardware ?

As you can see, there's clearly stated that you need "Arduino_STM32" folder, not "Arduino_STM32-master" which you will get after unzip.

I changed the name and list is Long = Thanks for hint.

example list does not changed