Thanks and you are right, several files are not overwrited.
It seems the overwriting works for all the directories apart for what is the admin directory, but this directory hasn't the same name in the upload package. At what moment of the process the files of this directory must be overwrited ?
The problem is probably here.
Is that perhaps your renamed admin folder?
PM me admin and FTP login details if you want me to take a look.
I think I have understood that in 1.4.2 it was "xxx" folder which contained admin php files and that now it is "admin" folder.
This would explain why there is no updating of "xxx" files. Do you think my forum could continue to use "xxx" files in place of "admin" ones ?
But, I haven't renamed any file neither any folder in the creation or the update process.
I can send you PM admin name and password, but for the moment there is no FTP process permitting to modify the files, because I don't need one.
The forum is on my own server which is connected to my local network. So a simple copy process in this environment is sufficient for me.
If there is no other solution, I'll search how to install such a FTP process, but it will take a few days for this.
Try uploading the admin files from the MyBB package to the coulisses folder on your server.
Thanks AJS, you're right, and I understand now what happened.
The admin folder name has effectively been modified, evidently by the server provider. I think I know now how to correct this problem.
Maybe it would be better to change in your previous response the renamed admin folder by "xxx".
Thanks a lot