When required, say an upgrade from 6 to 7 to 8, references with "owncloud7owncloud6" in this file must be changed to "owncloud8owncloud7". '''DO NOT''' change the "version". The changes can be made with a text editor or the following handy Linux command. The command looks through the "restored" config.php file in the new ownCloud7 upgrade instance, for occurrences of owncloud6 and changes them to owncloud7.