Multisite admin inaccessible

Hello,
I just managed to activate multisite in my wordpress install with an older site already running, however, I’m having this problem.

My wordpress install is in a folder (site.com/wordpress). I have the lines added in .htaccess from here (https://codex.wordpress.org/Giving_WordPress_Its_Own_Directory) to make the site work. Everythink OK up to here.

However, when I try to access the site network administration, the link leads to site.com/wp-admin/network which, of course, leads nowhere as the correct address would be site.com/wordpress/wp-admin/network (which works when I enter it manually).

Is there a solution?

Thanks a lot.