Unfortunately you ignored the Support Template and didn’t provide any information about your environment, therefore it is difficult to recommend anything special.
The only thing which I realized is, that you are masking underscores in the configuration (\_). You should not do this.
Write e.g. “'dbtableprefix' => 'oc_',” instead of “'dbtableprefix' => 'oc\_',”. (BTW, that’s the default therefore there is no need to set that parameter in the configuration).
Same with “'memcache.local' => '\\\\OC\\\\Memcache\\\\Redis',”. It should be “'memcache.local' => '\\OC\\Memcache\\Redis',”.
You should also check the syntax of “'trusted_domains' => array ( 0 => 'localhost', ),” because I don’t believe that you want to access Nextcloud using the hostname “localhost”.