Hi Daka Media KG,
to check your current FPM configuration file ( and the current depending used PHP - version ), you are able to search for the domain - specific *.conf - file, as for example:
locate YOUR-DOMAIN.COM.conf
or
locate SUB-DOMAIN.YOUR-DOMAIN.COM.conf
This will show you the exact location over the command line, as for example:
/opt/plesk/php/5.6/etc/php-fpm.d/YOUR-DOMAIN.COM.conf
or
/opt/plesk/php/5.6/etc/php-fpm.d/SUB-DOMAIN.YOUR-DOMAIN.COM.conf
As you can see in this example, the specific domain and the specific sub-domain use the additional Plesk 5.6 PHP - version and its configuration file is stored at "
/opt/plesk/php/5.6/etc/php-fpm.d/".
If the output shows two several locations ( for example "
/opt/plesk/php/5.6/etc/php-fpm.d/"
and "
/opt/plesk/php/7.0/etc/php-fpm.d/", then you will experience issues as described, because it is only possible to have ONE socket - file with the name "/var/www/vhosts/system/YOUR-DOMAIN.COM/
php-fpm.sock". If for some reason, the previous setting over the Plesk Control Panel for a specific PHP - handler exited with failures, you could experience differences between the stored location in the psa database, to the actual existent *.conf - file on your server. You are able to correct this by removing all found FPM - configuration files for that (sub)domain on your server and resetting the desired PHP - version over the Plesk - Control - Panel at : "
PHP settings"
( just choose another PHP version and re-change it back to the desired version afterwards ).