Enabling Apcu And Redis For Server Tweaks Not Working

I'm trying to enable both APC and Redis and tried to enable each one separately and cs-cart keeps going blank and can't even access the admin portal after the change. I did change it back to using database and it worked. Please let me know what I could do to enable the APCu and Redis image cache?

Tried to change the following options and my cs-cart goes blank.

$config['cache_backend'] = 'apc';

$config['session_backend'] = 'redis';

Have you tried changing them one at a time to see which one is breaking things? Suggest you start with defaults of 'file' and 'database'

Also, what's in your PHP error_log file? That will probably give you the best idea of what's wrong.

Is apc and redis installed/supported on your server?

Administration- logs, gear icon, php-information