Avoiding WordPress .htaccess rules on specific folder

Solution:

You don’t need multiple .htaccess you can put all the rules on the WordPress main .htaccess:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !^folder
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

Use either:

RewriteRule ^folder/start\.php$ /folder/index.php [R=301,L,NC]

Or

Redirect 301 /folder/start.php http://www.domain.com/folder/index.php

Don’t forget to change folder to your actual folder name.