to many menu links (urgent)

Hello, after changing the server i have the same problem with too many menu links.

If i copy this (php_value max_input_vars 5000) in my .htaccess file it doesn’t work. Im getting an Error.

This is in my original .htaccess:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
AddHandler x-httpd-php55 .php
</IfModule>
# END WordPress

Thank you for helping!