All in One SEO Pack installation

Hello,

I am a new WordPress user and I wish to install this plugin. (Before continuing, I have already done a research and it appears that the given solution doesn’t work for me)
When I want to configure it, I get this message “Fatal error: Cannot redeclare class All_in_One_SEO_Pack in /home/content/*/html/wp-admin/wp-content/plugins/all-in-one-seo-pack/aioseop.class.php on line 3”

My line 3: class All_in_One_SEO_Pack {

However, I don’t have any other plugin installed on WP… So there is no plugin conflict and I didn’t had any latest version of AIOSEOP, in fact it is the first plugin I want to install. I am also using the default theme of WP and I changed permissions from 604 to 755.

WP has been installed by Go Daddy if it matters.

Can someone help me with that?

Thank you