Thank you for your reply.
I placed the code on your start page (index.php) directory (install_gallery).
Nevertheless, I still cannot install it.
I wonder if this is not a problem of No serial or a rejection of my IP address because the first time I installed it again without problems?
I even tried to install it locally, but always with the same error.
I worked a lot with your products and this is the first time I have a big problem.