anything will do… as long as it is not a hit & miss game to activate the plug…
but… isn’t it “uber” complicated, I mean, a simple CRC check on the key as it is entered will do for most of stupid user errors like mine, just a “invalid key” before submitting would have saved me a lot of time searching…
Anyway, my problem is solved, I posted it juste for reference.
Thanks for your answer and your great work.