Maybe you like to post your htaccess-file content and we can see if there is something wrong?
I guess you have seen some other posts in the old forum and maybe this one with some examples of the htaccess-file content to work with Babel?
I just googled and saw this, which seems correct to me (except the wrong commenting-lines):
RewriteEngine On
RewriteBase /
# redirect all requests to /de/favicon.ico and /nl/favicon.ico
# to /favicon.ico
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(web|en)/favicon.ico$ favicon.ico [L,QSA]
# redirect all requests to /de/assets* and /nl/assets* to /assets*
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(web|en)/assets(.*)$ assets$2 [L,QSA]
# redirect all other requests to /de/* and /nl/*
# to index.php and set the cultureKey parameter
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(web|en)?/?(.*)$ index.php?cultureKey=$1&q=$2 [L,QSA]
You gotta change “en” to “es” for your site…
Friendly-URLs are turned on, right?