Make a backup copy of your 2.3.4 database and store it safely somewhere. Then, run this SQL, using PHPMyAdmin: This *should* update your 2.3.4 db to make it usable with the Responsive fileset. Please report any errors or omissions, here, thanks.   PLEASE READ THE FIRST FEW LINES OF COMMENTS IN THAT SQL CODE!!! Note that you will still need to install required some modules:   EG: Admin > Modules > Content > {install} Admin > Modules > Header