HTACCESS setEnv doesn't work for all servers

Just a thought - is your centOS setup running Apache or a compatible server that actually reads the .htaccess file? If it's, for example, nginx, you would have to do it completely differently.

500 is a good error. He/She should check the error log.


https://httpd.apache.org/docs/2.4/mod/mod_env.html

Try on the server a2enmod env