Thank you for your answer.
I can use :
XP on PC
For the web, I usually work with OS9 Mac.
When you open a miniBB script with BBEdit (7./0, very old), you have to choose the right format when you save.
Depending the format, the results are :
your page is a suite of "????"
you loose the french accents : é à ç, etc...
it is Ok, but an html bug checker will tell you that <head> is missing (and of course <head> exists).
At my first install of miniBB, I used Dremweaver as code editer, and it generates fatal errors in PHP scripts that I didn't touch !!!
I think it is just a problem of format when you save.
If you know yhe good format, and the good soft on Mac, thank you by advance.