Hello Paul, I try change bbcode but it does not work. I deleted all files bb_codes.php but no change :-/
Must how?

Kimi, then take the original bb_codes.php from the miniBB package and upload it back to your server. And before changes to the files you should always keep a backup of the previous executable version ;-)

To adapt and operation of the file you will find many suggestions for an appropriate search for bb_codes.

I try to change my boss, but it doesn't work.
I try to change my kid, but it doesn't work.
I try to change the world, but it doesn't work.

It looks like that's what your statement is about.

At first, I'd be curious to know what did you change, what the purpose was, how did you did it etc.
Without it, your question doesn't work for me ;)