Could you try adding a property
file = "ATTINY4313_dev_board"
after the name =
(I can't remember if we need the .fcdx suffix)
And delete everything above <root>
Such that it's the first line.

I can't be sure on the details without checking on my installation and I'm not at all familiar with AVR.

Quick look on my mobile, re the first issue, I think you need to change device name="ATTINY4313' to something like ATTINY4313_dev_board to make the fcd unique. As I recall, as an alternative, there's also a 'file' option property for the device section.
Hope that helps.

You could use the output of the Flowcode "Compile to Hex" and use the GUI version of STM32CubeProgrammer.

Your hardware would need to have USB and Boot0 switch implemented.

Looks like RPI_CAL_String.c is missing the FCLsz_TEMPSTR fix and other updates - one for Ben

I've not had chance to check your zip yet.
But have you tried a full database update?
The CAL string files have had some changes recently.

Your program looks OK. But we need to check that: a) the program is compiling OK on your machine, b) The device is being programmed correctly. The Flowcode Compiler Messages window will give you the answers to those questions. This output is also saved to the file button_pico.msg.txt So it would hel...

Login to your Flowcode account, then try the link again

FCLsz_TEMPSTR is undefined in PICO_CAL_String.c
this needs a fix from Matrix

I can’t help much further, I don’t have v8 or a STM32F469I disco board, only other thoughts are:
• Does it work OK in Flowcode simulation?
• What does a simple Initialise and print Hello World do?
• Try Flowcode V11?
• Maybe Matrix have a STM32F469I discovery board to test?