Hi Frank,
find / -name z-ocs* -print
/etc/httpd/conf.d/z-ocsinventory-server.conf
Settings in z-ocsinventory-server.conf
PerlSetEnv OCS_DB_USER myuser
PerlSetVar OCS_DB_PWD myuser_password
If user ocs is missing in DB then error
DBI connect('database=ocs;host=localhost;port=3306','ocs',...) failed: Access denied for user 'ocs'@'localhost' (using password: YES) at /usr/local/share/perl5/Apache/Ocsinventory/Server/System.pm line 187
So, var "PerlSetEnv OCS_DB_USER myuser" is not effective for some reason.
Restarted httpd service and also restarted the complete server. Error stays the same.