I’ve same problem in installation 2 WP in 1 server, i think the problem is in .htaccess. Permalink with domain.com/%post%/ doesn’t work, it only work at default. How to repair it to make it work with permalink domain.com/%post/.
I’v try to replace with
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /folder/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /folder/index.php [L]
</IfModule>
it still doesnt works.
Thx.