.htaccess issues using WP in Root and Program in Subdirs

Hi,

Installed WordPress in the Root, changed the installation into a Multi Site (Networked) version.

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]

# uploaded files
RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

I have other programs installed in the root, but using the .htaccess file causes the other programs not being available.

Moving WordPress into a subdir isn’t a solution.

How to change .htaccess so other programs in subdirs are available?

Tried searching in these forums but no solution found. Is this a weak spot of WordPress .htaccess combination?

I tried adding
RewriteEngine off
to the .htaccess and saved it to the subdir. No result.