Pauldy's House of Geek

cp /etc/php/7.2/fpm/pool.d/nextcloud.conf /etc/php/7.4/fpm/pool.d/

vi /etc/php/7.4/fpm/pool.d/nextcloud.conf

change the line 

listen = /run/php/php7.2-fpm.nextcloud.sock

to

listen = /run/php/php7.4-fpm.nextcloud.sock

Next we need to install some items that for whatever reason don’t get upgraded if you are using something other than pgsql change that here too.

apt install php7.4-fpm php-pgsql php-curl php7.4-xml php7.4-gd php-json php-mbstring php-zip php-bz2 php-intl php-ldap php-imap php-bcmath php-gmp php-redis php-igbinary php-memcache

systemctl enable php7.4-fpm

service php7.4-fpm start

grep php7.2-fpm `find ./`

change all these instances to php7.4-fpm

service apache2 restart

Doing these steps should solve the following errors:

No such file or directory: AH02454: FCGI: attempt to connect to Unix domain socket /run/php/php7.2-fpm.nextcloud.sock

Memcache \\OC\\Memcache\\Redis not available for local cache

Got error ‘PHP message: PHP Fatal error: Uncaught Doctrine\\DBAL\\DBALException: Failed to connect to the database: An exception occurred in driver: could not find driver

failed to make connection to backend: httpd-UDS